Communication apparatus and communication method

ABSTRACT

Provided are M signal processors that respectively generate modulated signals for M reception apparatuses (where M is an integer equal to 2 or greater), a multiplexing signal processor, and N antenna sections (where N is an integer equal to 1 or greater). When transmitting multiple streams, each of the M signal processors generates two mapped signals, generates first and second precoded signals by precoding the two mapped signals, periodically changes the phase of signal points in the IQ plane with respect to the second precoded signal, outputs the phase-changed signal, and outputs the first precoded signal and the phase-changed second precoded signal as two modulated signals. When transmitting a single stream, each of the M signal processor outputs a single modulated signal. The multiplexing signal processor multiplexes the modulated signals output from the M signal processors, and generates N multiplexed signals. The N antenna sections respectively transmit the N multiplexed signals.

BACKGROUND 1. Technical Field

The present disclosure relates to a transmission apparatus and atransmission method.

2. Description of the Related Art

In the related art, a communication method called multiple-inputmultiple-output (MIMO), for example, exists as a communication methodusing multiple antennas. In multi-antenna communication for a singleuser as typified by MIMO, by modulating each of multiple sequences oftransmission data, and transmitting each modulated signal at the sametime from different antennas, the communication speed of the data isincreased.

FIG. 33 is a diagram illustrating an example of a configuration of atransmission apparatus based on the Digital Video Broadcasting-NextGeneration Handheld (DVB-NGH) standard, in which there are twotransmission antennas and two modulated signals to transmit(transmission streams), as described in “MIMO for DVB-NGH, the nextgeneration mobile TV broadcasting,” IEEE Commun. Mag., vol. 57, no. 7,pp. 130-137, July 2013. In the transmission apparatus, data 1 is inputand coded by a coder 2 to obtain data 3, which is divided into data 5Aand data 5B by a distributor 4. The data 5A is subjected to aninterleaving process by an interleaver 4A, and a mapping process by amapper 6A. Similarly, the data 5B is subjected to an interleavingprocess by an interleaver 4B, and a mapping process by a mapper 6B. Thecoding process in the coder 2, the interleaving processes in theinterleavers 4A and 4B, and the mapping processes in the mappers 6A and6B are executed according to settings information included in a frameconfiguration signal 13.

Weight combiners 8A and 8B have the mapped signals 7A and 7B as inputand execute weight combining on them, respectively. With thisarrangement, weighted combined signals 9A and 16B are generated. Afterthat, the weighted combined signal 16B is phase-changed by a phasechanger 17B, and a phase-changed signal 9B is output. Additionally,radio sections 10A and 10B execute, for example, processes related toorthogonal frequency-division multiplexing (OFDM), frequency conversionand amplification, and a transmission signal 11A is transmitted from anantenna 12A, while a transmission signal 11B is transmitted from anantenna 12B. The weight combining process in the weight combiners 8A and8B as well as the phase change process in the phase changer 17B areexecuted on the basis of signal processing method information 115generated by a signal processing method information generator 114. Thesignal processing method information generator 114 generates the signalprocessing method information 115 on the basis of the frameconfiguration signal 13. At this time, in the phase changer 17B, forexample, 9 phase change values are provided, and phase change with aperiod of 9 is executed regularly.

With this arrangement, in an environment in which direct waves aredominant, there is an increased possibility of being able to avoidfalling into a steady reception state, and the received signal qualityof data at a reception apparatus on the other end of communication maybe improved.

Additional information is described in “Standard conformable antennadiversity techniques for OFDM and its application to the DVB-T system,”IEEE Globecom 2001, pp. 3100-3105, November 2001, and also in IEEEP802.11n(D3.00) Draft STANDARD for InformationTechnology-Telecommunications and information exchange betweensystems-Local and metropolitan area networks-Specificrequirements-Part11: Wireless LAN Medium Access Control (MAC) andPhysical Layer (PHY) specifications, 2007.

SUMMARY

However, the transmission apparatus in FIG. 33 uses identical times andidentical frequencies, and does not consider the transmission ofmodulated signals to multiple terminals (multiple users).

One non-limiting and exemplary embodiment provides a transmissionapparatus that transmits modulated signals to multiple terminals(multiple users) using identical times and identical frequencies, beinga transmission apparatus that, when transmitting the modulated signalsof multiple streams in an environment in which direct waves aredominant, is able to avoid falling into a steadily degraded receptionstate. With this arrangement, the received signal quality of data at areception apparatus on the other end of communication may be improved.

In one general aspect, the techniques disclosed here feature atransmission apparatus comprising: M signal processors that respectivelygenerate modulated signals with respect to M reception apparatuses(where M is an integer equal to 2 or greater), wherein each of the Msignal processors includes a precoder that, in a case of transmittingmultiple streams to a corresponding reception apparatus, generates twomapped signals to transmit to the corresponding reception apparatus, andgenerates a first precoded signal and a second precoded signal byprecoding the two mapped signals, and a phase changer that periodicallychanges a phase of signal points in an IQ plane with respect to thesecond precoded signal, and outputs a phase-changed signal, outputs thefirst precoded signal and the phase-changed signal as two modulatedsignals, and each of the M signal processors outputs a single modulatedsignal in a case of transmitting a single stream to the correspondingreception apparatus; a multiplexing signal processor that generates Nmultiplexed signals (where N is an integer equal to 1 or greater) bymultiplexing the modulated signals output from each of the M signalprocessors; and N antenna sections that include at least one antennaelement each, and respectively transmit the N multiplexed signals.

It should be noted that general or specific embodiments may beimplemented as a system, a method, an integrated circuit, a computerprogram, a storage medium, or any selective combination thereof.

The transmission apparatus according to the present disclosure is ableto avoid falling into a steadily degraded reception state whentransmitting the modulated signals of multiple streams to each terminal(each user) in an environment in which direct waves are dominant. Withthis arrangement, the received signal quality of data at a receptionapparatus on the other end of communication may be improved.

Additional benefits and advantages of the disclosed embodiments willbecome apparent from the specification and drawings. The benefits and/oradvantages may be individually obtained by the various embodiments andfeatures of the specification and drawings, which need not all beprovided in order to obtain one or more of such benefits and/oradvantages.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram illustrating an example of a configuration of atransmission apparatus according to an embodiment of the presentdisclosure;

FIG. 2 is a diagram illustrating an example of a configuration of asignal processor for user #p;

FIG. 3 is a diagram illustrating an example of a configuration of thesignal processor in FIG. 2;

FIG. 4 is a diagram illustrating a different example from FIG. 3 of aconfiguration of the signal processor in FIG. 2;

FIG. 5 is a diagram illustrating an example of a configuration of aradio section $n in which OFDM is used;

FIG. 6 is a diagram illustrating an example of a configuration of theantenna section in FIG. 1;

FIG. 7 is a diagram illustrating an example of a configuration of aportion related to control information generation for generating thecontrol information symbol signal in FIG. 4;

FIG. 8 is a diagram illustrating an example of the frame configurationof a first baseband signal for user #p;

FIG. 9 is a diagram illustrating an example of the frame configurationof a second baseband signal for user #p;

FIG. 10 is a diagram illustrating a different example of the frameconfiguration of a first baseband signal for user #p;

FIG. 11 is a diagram illustrating a different example of the frameconfiguration of a second baseband signal for user #p;

FIG. 12 is a diagram illustrating an example of a method of arrangingsymbols with respect to the time axis;

FIG. 13 is a diagram illustrating an example of a method of arrangingsymbols with respect to the frequency axis;

FIG. 14 is a diagram illustrating an example of arranging symbols withrespect to the time-frequency axes;

FIG. 15 is a diagram illustrating an example of arranging symbols withrespect to the time axis;

FIG. 16 is a diagram illustrating an example of arranging symbols withrespect to the frequency axis;

FIG. 17 is a diagram illustrating an example of arranging symbols withrespect to the time-frequency axes;

FIG. 18 is a diagram illustrating a configuration in a case of includingan interleaver in a multiplexing signal processor;

FIG. 19 is a diagram illustrating an example of a configuration of areception apparatus according to the present embodiment;

FIG. 20 is a diagram illustrating the relationship between thetransmission apparatus and the reception apparatus;

FIG. 21 is a diagram illustrating an example of a configuration of theantenna section in FIG. 19;

FIG. 22 is a diagram illustrating an example of a configuration providedtogether with the transmission apparatus of FIG. 1 in a base station(AP);

FIG. 23 is a diagram illustrating an example of a configuration providedtogether with the reception apparatus of FIG. 19 in a terminal;

FIG. 24 is a diagram illustrating an example of the relationship betweena base station (AP) and terminals;

FIG. 25 is a diagram illustrating an example of the temporal flow ofcommunication between a base station (AP) and terminals;

FIG. 26 is a diagram illustrating a different example from FIG. 3 of aconfiguration of the signal processor in FIG. 2;

FIG. 27 is a diagram illustrating an example of communication between abase station (AP) and a terminal #p;

FIG. 28 is a diagram illustrating an example of data included inreceiving ability notification symbols;

FIG. 29 is a diagram illustrating a different example from FIG. 28 ofdata included in reception capability notification symbols;

FIG. 30 is a diagram illustrating a different example from FIGS. 28 and29 of data included in reception capability notification symbols;

FIG. 31 is a diagram illustrating an example of a configuration of asignal processor for user #p;

FIG. 32 is a diagram illustrating an example of a configuration of asignal processor for user #p;

FIG. 33 is a diagram illustrating an example of a configuration of atransmission apparatus based on the DVB-NGH standard described in NPL 1;

FIG. 34 is a diagram illustrating an example of a configuration of aterminal #p on the other end of communication with the base stationillustrated in FIG. 24;

FIG. 35 is a diagram illustrating an example of a configuration of theterminal #p illustrated in FIG. 34;

FIG. 36 is a diagram illustrating an example of a frame configuration ofa modulated signal of a single stream transmitted using a multi-carriertransmission scheme such as OFDM;

FIG. 37 is a diagram illustrating an example of a frame configuration ofa modulated signal of a single stream transmitted using a single-carriertransmission scheme;

FIG. 38 is a diagram illustrating yet another example of a configurationof the signal processor in FIG. 2;

FIG. 39 is a diagram illustrating yet another example of a configurationof the signal processor in FIG. 2;

FIG. 40 is a diagram illustrating a first example of disposing phasechangers upstream and downstream of a weight combiner;

FIG. 41 is a diagram illustrating a second example of disposing phasechangers upstream and downstream of a weight combiner;

FIG. 42 is a diagram illustrating a third example of disposing phasechangers upstream and downstream of a weight combiner;

FIG. 43 is a diagram illustrating a fourth example of disposing phasechangers upstream and downstream of a weight combiner;

FIG. 44 is a diagram illustrating a fifth example of disposing phasechangers upstream and downstream of a weight combiner;

FIG. 45 is a diagram illustrating a sixth example of disposing phasechangers upstream and downstream of a weight combiner;

FIG. 46 is a diagram illustrating a seventh example of disposing phasechangers upstream and downstream of a weight combiner;

FIG. 47 is a diagram illustrating an eighth example of disposing phasechangers upstream and downstream of a weight combiner;

FIG. 48 is a diagram illustrating a ninth example of disposing phasechangers upstream and downstream of a weight combiner;

FIG. 49 is a diagram illustrating a different example from FIG. 2 of aconfiguration of a signal processor for user #p;

FIG. 50A is a diagram illustrating a first example of a state of signalpoints transmitted in a transmission apparatus that includes theconfiguration of FIG. 3;

FIG. 50B is a diagram illustrating a first example of a state of signalpoints of a signal received in a reception apparatus on the other end ofcommunication with a transmission apparatus that includes theconfiguration of FIG. 3;

FIG. 51A is a diagram illustrating a second example of a state of signalpoints of a signal transmitted in a transmission apparatus that includesthe configuration of FIG. 3;

FIG. 51B is a diagram illustrating a second example of a state of signalpoints of a signal received in a reception apparatus on the other end ofcommunication with a transmission apparatus that includes FIG. 3;

FIG. 52 is a diagram illustrating a different example from FIG. 1, ofthe configuration of a transmission apparatus of a base station (AP);

FIG. 53 is a diagram illustrating a different example from FIGS. 28, 29,and 30 of data included in reception capability notification symbols;

FIG. 54 is a diagram illustrating an example of a configuration of aframe;

FIG. 55 is a diagram illustrating an example of carrier groups ofmodulated signals transmitted by a base station or AP;

FIG. 56 is a diagram illustrating a different example from FIG. 55 ofcarrier groups of modulated signals transmitted by a base station or AP;

FIG. 57 is a diagram illustrating an example of a configuration in whichphase changers are added;

FIG. 58 is a diagram illustrating a first exemplary configuration of thesignal processor for user #p in FIGS. 1 and 52;

FIG. 59 is a diagram illustrating a second exemplary configuration ofthe signal processor for user #p in FIGS. 1 and 52;

FIG. 60 is a diagram illustrating a first example of a configurationincluded in a control information symbol or the like;

FIG. 61 is a diagram illustrating a second example of a configurationincluded in a control information symbol or the like;

FIG. 62 is a diagram illustrating an example of a configuration of afirst signal processor;

FIG. 63 is a diagram illustrating an example of a configuration of asecond signal processor;

FIG. 64 is a diagram illustrating an example of the relationship betweena base station (AP) and a terminal; and

FIG. 65 is a diagram illustrating a different example from FIG. 1 of theconfiguration of a transmission apparatus of a base station (AP).

DETAILED DESCRIPTION

Hereinafter, exemplary embodiments of the present disclosure will bedescribed in detail and with reference to the drawings. Note that eachof the embodiments described hereinafter is an example, and the presentdisclosure is not limited to these embodiments.

Embodiment 1

A transmission method, transmission apparatus, reception method, andreception apparatus of the present embodiment will be described indetail.

Example of Configuration of Transmission Apparatus in Present Embodiment

FIG. 1 is a diagram illustrating an example of the configuration of thetransmission apparatus in the present embodiment. The transmissionapparatus illustrated in FIG. 1 is, for example, a base station, anaccess point, a broadcasting station, or the like. The transmissionapparatus is an apparatus that generates and transmits multiplemodulated signals for transmission to M reception apparatuses(terminals) of user #1 to user #M (where M is an integer equal to 2 orgreater).

The transmission apparatus illustrated in FIG. 1 is provided with a user#1 signal processor 102_1 to a user #M signal processor 102_M, amultiplexing signal processor 104, and a radio section $1 (106_1) to aradio section $N (106_N), an antenna section $1 (108_1) to an antennasection $N (108_N) (where N is an integer equal to 1 or greater).

The user #1 signal processor 102_1 accepts a control signal 100 and user#1 data 101_1 as input. The user #1 signal processor 102_1 executessignal processing on the basis of information about the transmissionmethod for generating a user #1 modulated signal (for example, anerror-correcting coding method (the code rate of the error-correctingcode, the code length of the error-correcting code), a modulationscheme, a transmission method (for example, single-stream transmission,multi-stream transmission), and the like) included in the control signal100, and generates a user #1 first baseband signal 103_1_1 and/or a user#1 second baseband signal 103_1_2. The user #1 signal processor 102_1outputs the generated user #1 first baseband signal 103_1_1 and/or user#1 second baseband signal 103_1_2 to the multiplexing signal processor104.

For example, in the case in which information indicating thatmulti-stream transmission has been selected is included in the controlsignal 100, the user #1 signal processor 102_1 generates the user #1first baseband signal 103_1_1 and the user #1 second baseband signal103_1_2. In the case in which information indicating that single-streamtransmission has been selected is included in the control signal 100,the user #1 signal processor 102_1 generates the user #1 first basebandsignal 103_1_1.

Similarly, the user #2 signal processor 102_2 accepts the control signal100 and user #2 data 101_2 as input. The user #2 signal processor 102_2executes signal processing on the basis of information about thetransmission method for generating a user #2 modulated signal (forexample, an error-correcting coding method (the code rate of theerror-correcting code, the code length of the error-correcting code), amodulation scheme, a transmission method (for example, single-streamtransmission, multi-stream transmission), and the like) included in thecontrol signal 100, and generates a user #2 first baseband signal103_2_1 and/or a user #2 second baseband signal 103_2_2. The user #2signal processor 102_2 outputs the generated user #2 first basebandsignal 103_2_1 and/or user #2 second baseband signal 103_2_2 to themultiplexing signal processor 104.

For example, in the case in which information indicating thatmulti-stream transmission has been selected is included in the controlsignal 100, the user #2 signal processor 102_2 generates the user #2first baseband signal 103_2_1 and the user #2 second baseband signal103_2_2. In the case in which information indicating that single-streamtransmission has been selected is included in the control signal 100,the user #2 signal processor 102_2 generates the user #2 first basebandsignal 103_2_1.

Similarly, the user #M signal processor 102_M accepts the control signal100 and user #2 data 101_M as input. The user #M signal processor 102_Mexecutes signal processing on the basis of information about thetransmission method for generating a user #M modulated signal (forexample, an error-correcting coding method (the code rate of theerror-correcting code, the code length of the error-correcting code), amodulation scheme, a transmission method (for example, single-streamtransmission, multi-stream transmission), and the like) included in thecontrol signal 100, and generates a user #M first baseband signal103_M_1 and/or a user #M second baseband signal 103_M_2. The user #Msignal processor 102_M outputs the generated user #M first basebandsignal 103_M_1 and/or user #M second baseband signal 103_M_2 to themultiplexing signal processor 104.

For example, in the case in which information indicating thatmulti-stream transmission has been selected is included in the controlsignal 100, the user #M signal processor 102_M generates the user #Mfirst baseband signal 103_M_1 and the user #M second baseband signal103_M_2. In the case in which information indicating that single-streamtransmission has been selected is included in the control signal 100,the user #M signal processor 102_M generates the user #M first basebandsignal 103_M_1.

Consequently, a user #p signal processor 102_p (where p is an integerfrom 1 to M) accepts the control signal 100 and user #p data 101_p asinput. The user #p signal processor 102_p executes signal processing onthe basis of information about the transmission method for generating auser #p modulated signal (for example, an error-correcting coding method(the code rate of the error-correcting code, the code length of theerror-correcting code), a modulation scheme, a transmission method (forexample, single-stream transmission, multi-stream transmission), and thelike) included in the control signal 100, and generates a user #p firstbaseband signal 103_p_1 and/or a user #p second baseband signal 103_p_2.The user #p signal processor 102_p outputs the generated user #p firstbaseband signal 103_p_1 and/or user #p second baseband signal 103_p_2 tothe multiplexing signal processor 104.

For example, in the case in which information indicating thatmulti-stream transmission has been selected is included in the controlsignal 100, the user #p signal processor 102_p generates the user #pfirst baseband signal 103_p_1 and the user #p second baseband signal103_p_2. In the case in which information indicating that single-streamtransmission has been selected is included in the control signal 100,the user #p signal processor 102_p generates the user #p first basebandsignal 103_p_1.

Note that the configuration of each from the user #1 signal processor102_1 to the user #M signal processor 102_M will be described later bytaking the configuration of the user #p signal processor as an example.

Note that the control signal 100 includes information indicating whethermulti-stream transmission or single-stream transmission has beenselected with respect to each from the user #1 signal processor 102_1 tothe user #M signal processor 102_M.

The multiplexing signal processor 104 accepts the control signal 100,the user #1 first baseband signal 103_1_1, the user #1 second basebandsignal 103_1_2, the user #2 first baseband signal 103_2_1, the user #2second baseband signal 103_2_2, . . . , the user #M first basebandsignal 103_M_1, the user #M second baseband signal 103_M_2, and a(common) reference signal 199 as input. The multiplexing signalprocessor 104 performs multiplexing signal processing on the basis ofthe control signal 100, and generates a multiplexed signal $1 basebandsignal 105_1 to a multiplexed signal $N baseband signal 105_N (where Nis an integer equal to 1 or greater). The multiplexing signal processor104 outputs the generated multiplexed signal $1 baseband signal 105_1 tothe multiplexed signal $N baseband signal 105_N to corresponding radiosections (radio section $1 to radio section $N).

The (common) reference signal 199 is a signal transmitted from thetransmission apparatus for the reception apparatus to estimate thepropagation environment. The (common) reference signal 199 is insertedinto the baseband signal of each user. Note that the multiplexing signalprocessing will be described later.

The radio section $1 (106_1) accepts the control signal 100 and themultiplexed signal $1 baseband signal 105_1 as input. On the basis ofthe control signal 100, the radio section $1 (106_1) executes processessuch as frequency conversion and amplification, and outputs atransmission signal 107_1 to the antenna section $1 (108_1).

The antenna section $1 (108_1) accepts the control signal 100 and thetransmission signal 107_1 as input. The antenna section $1 (108_1)processes the transmission signal 107_1 on the basis of the controlsignal 100. However, in the antenna section $1 (108_1), the controlsignal 100 may also not be present as input. Subsequently, thetransmission signal 107_1 is output as a radio wave from the antennasection $1 (108_1).

The radio section $2 (106_2) accepts the control signal 100 and themultiplexed signal $2 baseband signal 105_2 as input. On the basis ofthe control signal 100, the radio section $2 (106_2) executes processessuch as frequency conversion and amplification, and outputs atransmission signal 107_2 to the antenna section $2 (108_2).

The antenna section $2 (108_2) accepts the control signal 100 and thetransmission signal 107_2 as input. The antenna section $2 (108_2)processes the transmission signal 107_2 on the basis of the controlsignal 100. However, in the antenna section $2 (108_2), the controlsignal 100 may also not be present as input. Subsequently, thetransmission signal 107_2 is output as a radio wave from the antennasection $2 (108_2).

The radio section $N (106_N) accepts the control signal 100 and themultiplexed signal $N baseband signal 105N as input. On the basis of thecontrol signal 100, the radio section $N (106_N) executes processes suchas frequency conversion and amplification, and outputs a transmissionsignal 107_N to the antenna section $N (108_N).

The antenna section $N (108_N) accepts the control signal 100 and thetransmission signal 107_N as input. The antenna section $N (108_N)processes the transmission signal 107_N on the basis of the controlsignal 100. However, in the antenna section $N (108_N), the controlsignal 100 may also not be present as input. Subsequently, thetransmission signal 107_N is output as a radio wave from the antennasection $N (108_N).

Consequently, the radio section $n (106_n) (where n is an integer from 1to N) accepts the control signal 100 and the multiplexed signal $nbaseband signal 105_n as input. On the basis of the control signal 100,the radio section $n (106_n) executes processes such as frequencyconversion and amplification, and outputs a transmission signal 107_n tothe antenna section $n (108_n).

The antenna section $n (108_n) accepts the control signal 100 and thetransmission signal 107_n as input. The antenna section $n (108_n)processes the transmission signal 107_n on the basis of the controlsignal 100. However, in the antenna section $n (108_n), the controlsignal 100 may also not be present as input. Subsequently, thetransmission signal 107_n is output as a radio wave from the antennasection $n (108_n).

Note that an example of the configurations of the radio sections $1 to$N and the antenna sections $1 to $N will be described later.

The control signal 100 may be generated on the basis of informationtransmitted to the transmission apparatus in FIG. 1 by the receptionapparatus on the other end of communication in FIG. 1, or thetransmission apparatus in FIG. 1 may be provided with an input section,and the control signal 100 may be generated on the basis of informationinput from the input section.

Note that in the transmission apparatus in FIG. 1, not all from the user#1 signal processor (102_1) to the user #M signal processor (102_M) maybe operating. All may be operating, or some may be operating. In otherwords, the number of users that the transmission apparatus iscommunicating with is from 1 to M. The number of communication peers(users) to which the transmission apparatus in FIG. 1 transmits amodulated signal is from 1 to M.

Also, not all from the radio section $1 (106_1) to the radio section $N(106_N) may be operating. All may be operating, or some may beoperating. Also, not all from the antenna section $1 (108_1) to theantenna section $N (108_N) may be operating. All may be operating, orsome may be operating.

As above, the transmission apparatus in FIG. 1 is able to transmit themodulated signals (baseband signals) of multiple users using identicaltimes and identical frequencies (bands) by using multiple antennas.

For example, the transmission apparatus in FIG. 1 is able to transmitthe user #1 first baseband signal 103_1_1, the user #1 second basebandsignal 103_1_2, the user #2 first baseband signal 103_2_1, and the user#2 second baseband signal 103_2_2 using identical times and identicalfrequencies (bands). Also, the transmission apparatus in FIG. 1 is ableto transmit the user #1 first baseband signal 103_1_1, the user #1second baseband signal 103_1_2, and the user #2 first baseband signal103_2_1 using identical times and identical frequencies (bands). Notethat the combinations of modulated signals (baseband signals) ofmultiple users to which the transmission apparatus in FIG. 1 transmitsare not limited to these examples.

<Example of Configuration of User #p Signal Processor>

Next, the configuration of each from the user #1 signal processor 102_1to the user #M signal processor 102_M in FIG. 1 will be described bytaking the configuration of the user #p signal processor 102_p as anexample. FIG. 2 is a diagram illustrating an example of a configurationof the user #p signal processor 102_p.

The user #p signal processor 102_p is provided with an error-correctingcoder 202, a mapper 204, and a signal processor 206.

The error-correcting coder 202 accepts user #p data 201 and a controlsignal 200 as input. The control signal 200 corresponds to the controlsignal 100 in FIG. 1, and the user #p data 201 corresponds to the user#p data 101_p in FIG. 1. The error-correcting coder 202 executeserror-correcting coding on the basis of information related toerror-correcting coding (for example, error-correcting code information,the code length (block length), and the code rate) included in thecontrol signal 200, and outputs user #p coded data 203 to the mapper204.

Note that the error-correcting coder 202 may also be provided with aninterleaver. In the case of being provided with an interleaver, theerror-correcting coder 202 sorts the data after coding, and outputs user#p coded data 203.

The mapper 204 accepts the user #p coded data 203 and the control signal200 as input. The mapper 204 executes mapping corresponding to themodulation scheme on the basis of information about the modulationscheme included in the control signal 200, and generates a user #pmapped signal (baseband signal) 205_1 and/or mapped signal (basebandsignal) 205_2. The mapper 204 outputs the generated user #p mappedsignal (baseband signal) 205_1 and/or mapped signal (baseband signal)205_2 to the signal processor 206.

Note that in the case in which the control signal 200 includesinformation indicating that multi-stream transmission has been selected,the mapper 204 divides the user #p coded data 203 into a first sequenceand a second sequence. Subsequently, the mapper 204 uses the firstsequence to generate a user #p mapped signal 205_1, and uses the secondsequence to generate a user #p mapped signal 205_2. At this time, thefirst sequence and the second sequence are assumed to be different.However, it is possible to carry out the above similarly even if thefirst sequence and the second sequence are the same.

Also, in the case in which the control signal 200 includes informationindicating that multi-stream transmission has been selected, the mapper204 may divide the user #p coded data 203 into three or more sequences,use each sequence to execute mapping, and generate three or more mappedsignals. In this case, the three or more sequences may be different fromeach other, but some or all of the three or more sequences may also bethe same sequences.

In addition, in the case in which the control signal 200 includesinformation indicating that single-stream transmission has beenselected, the user #p coded data 203 is treated as a single sequence togenerate the user #p mapped signal 205_1.

The signal processor 206 accepts the user #p mapped signal 205_1 and/orthe user #p mapped signal 205_2, as well as a signal group 210 and thecontrol signal 200 as input. On the basis of the control signal 200, thesignal processor 206 executes signal processing, and outputs user #psignal-processed signals 207_A and 207_B. The user #p signal-processedsignal 207_A corresponds to the user #p first baseband signal 103_p_1 inFIG. 1, and the user #p signal-processed signal 207_B corresponds to theuser #p second baseband signal 103_p_2 in FIG. 1.

At this time, the user #p signal-processed signal 207_A is designatedup1(i), and the user #p signal-processed signal 207_B is designatedup2(i). Herein, i is taken to be the symbol number. For example, i is aninteger equal to 0 or greater.

Next, the configuration of the signal processor 206 in FIG. 2 will bedescribed using FIG. 3.

<Example of Configuration of Signal Processor 206>

FIG. 3 is a diagram illustrating an example of the configuration of thesignal processor 206 in FIG. 2. The signal processor 206 is providedwith a weight combiner 303, a phase changer 305B, an inserter 307A, aninserter 307B, and a phase changer 309B. Note that FIG. 3 illustrates acase in which the mapper 204 in FIG. 2 generates the user #p mappedsignal 205_1 and the user #p mapped signal 205_2 on the basis ofinformation indicating that multi-stream transmission has been selected.

The weight combiner 303 (precoder) 303 accepts a user #p mapped signal301A, a user #p mapped signal 301B, and a control signal 300 as input.The user #p mapped signal 301A corresponds to the user #p mapped signal205_1 in FIG. 2, and the user #p mapped signal 301B corresponds to theuser #p mapped signal 205_2 in FIG. 2. Also, the control signal 300corresponds to the control signal 200 in FIG. 2.

On the basis of the control signal 300, the weight combiner 303 executesweight combining (precoding), and generates a user #p weighted signal304A and a user #p weighted signal 304B. The weight combiner 303 outputsthe user #p weighted signal 304A to the inserter 307A. The weightcombiner 303 outputs the user #p weighted signal 304B to the phasechanger 305B.

The user #p mapped signal 301A is designated sp1(t), the user #p mappedsignal 301B is designated sp2(t), the user #p weighted signal 304A isdesignated zp1(t), and the user #p weighted signal 304B is designatedzp2′(t). Note that t is taken to be time as an example. Also, sp1(t),sp2(t), zp1(t), and zp2′(t) are taken to be defined as complex numbers.Consequently, sp1(t), sp2(t), zp1(t), and zp2′(t) may also be realnumbers.

In this case, the weight combiner 303 executes computation based on thefollowing Formula (1).

$\begin{matrix}{\begin{pmatrix}{zp1(i)} \\{zp{2'}(i)}\end{pmatrix} = {\begin{pmatrix}a & b \\c & d\end{pmatrix}\begin{pmatrix}{sp1(i)} \\{sp2(i)}\end{pmatrix}}} & (1)\end{matrix}$In Formula (1), a, b, c, and d are defined as complex numbers. However,a, b, c, and d may also be real numbers. Note that i is taken to be thesymbol number.

The phase changer 305B accepts the weighted signal 304B and the controlsignal 300 as input. On the basis of the control signal 300, the phasechanger 305B changes the phase of the weighted signal 304B, and outputsa phase-changed signal 306B to the inserter 307B. Note that thephase-changed signal 306B is designated zp2(t). Herein, zp2(t) is takento be defined as a complex number. Note that zp2(t) may also be a realnumber.

The specific operation of the phase changer 305B will be described. Inthe phase changer 305B, assume that a phase change of yp(i) is performedon zp2′(i). Consequently, it is possible to expresszp2(i)=yp(i)×zp2′(i). Herein, i is taken to be the symbol number (wherei is an integer equal to 0 or greater).

For example, the phase changer 305B sets the value of the phase changeexpressed as yp(i) like the following Formula (2).

$\begin{matrix}{{{yp}(i)} = e^{j\frac{2 \times  \times i}{Np}}} & (2)\end{matrix}$In Formula (2), j is the imaginary unit. Also, Np is an integer equal to2 or greater, and indicates the period of the phase change. If Np is setto an odd number equal to 3 or greater, there is a possibility that thereceived signal quality of the data will improve. However, Formula (2)is merely one example, and the value of the phase change set in thephase changer 305B is not limited thereto. Accordingly, the phase changevalue is taken to be expressed as yp(i)=e^(j×δp(i)).

At this time, by using the phase change value yp(i)=e^(j×δp(i)) andFormula (1), zp1(i) and zp2(i) may be expressed as the following Formula(3).

$\begin{matrix}\begin{matrix}{\begin{pmatrix}{zp1(i)} \\{zp2(i)}\end{pmatrix} = {\begin{pmatrix}1 & 0 \\0 & {y{p(i)}}\end{pmatrix}\begin{pmatrix}{zp1(i)} \\{zp{2'}(i)}\end{pmatrix}}} \\{= {\begin{pmatrix}1 & 0 \\0 & {{yp}(i)}\end{pmatrix}\begin{pmatrix}a & b \\c & d\end{pmatrix}\begin{pmatrix}{sp1(i)} \\{sp2(i)}\end{pmatrix}}} \\{= {\begin{pmatrix}1 & 0 \\0 & e^{j \times {{\delta p}{(i)}}}\end{pmatrix}\begin{pmatrix}a & b \\c & d\end{pmatrix}\begin{pmatrix}{{sp}\; 1(i)} \\{sp2(i)}\end{pmatrix}}}\end{matrix} & (3)\end{matrix}$Note that δp(i) is a real number. Additionally, zp1(i) and zp2(i) aretransmitted from the transmission apparatus at identical times andidentical frequencies (identical frequency bands).

In Formula (3), the phase change value yp(i) is not limited to Formula(2), and for example, a method that changes the phase periodically orregularly is conceivable.

The matrix used in the computation of the weight combiner 303illustrated in Formula (1) and Formula (3) will be described. The matrixused in the computation of the weight combiner 303 is expressed as Fp,as illustrated in the following Formula (4).

$\begin{matrix}{\begin{pmatrix}a & b \\c & d\end{pmatrix} = {Fp}} & (4)\end{matrix}$

For example, for the matrix Fp, it is conceivable to use any of thematrices from Formula (5) to Formula (12) below.

$\begin{matrix}{{Fp} = \begin{pmatrix}{\beta \times e^{j0}} & {\beta \times \alpha \times e^{j0}} \\{\beta \times \alpha \times e^{j0}} & {\beta \times e^{j}}\end{pmatrix}} & (5) \\{{Fp} = {\frac{1}{\sqrt{\alpha^{2} + 1}}\begin{pmatrix}e^{j0} & {\alpha \times e^{j0}} \\{\alpha \times e^{j0}} & e^{j}\end{pmatrix}}} & (6) \\{{Fp} = \begin{pmatrix}{\beta \times e^{j0}} & {\beta \times \alpha \times e^{j}} \\{\beta \times \alpha \times e^{j0}} & {\beta \times e^{j0}}\end{pmatrix}} & (7) \\{{Fp} = {\frac{1}{\sqrt{\alpha^{2} + 1}}\begin{pmatrix}e^{j0} & {\alpha \times e^{j\pi}} \\{\alpha \times e^{j0}} & e^{j0}\end{pmatrix}}} & (8) \\{{Fp} = \begin{pmatrix}{\beta \times \alpha \times e^{j0}} & {\beta \times e^{j\pi}} \\{\beta \times e^{j0}} & {\beta \times \alpha \times e^{j0}}\end{pmatrix}} & (9) \\{{Fp} = {\frac{1}{\sqrt{\alpha^{2} + 1}}\begin{pmatrix}{\alpha \times e^{j0}} & e^{j\pi} \\e^{j0} & {\alpha \times e^{j0}}\end{pmatrix}}} & (10) \\{{Fp} = \begin{pmatrix}{\beta \times \alpha \times e^{j0}} & {\beta \times e^{j0}} \\{\beta \times e^{j0}} & {\beta \times \alpha \times e^{j}}\end{pmatrix}} & (11) \\{{Fp} = {\frac{1}{\sqrt{\alpha^{2} + 1}}\begin{pmatrix}{\alpha \times e^{j0}} & e^{j0} \\e^{j0} & {\alpha \times e^{j}}\end{pmatrix}}} & (12)\end{matrix}$Note that in Formula (5) to Formula (12), α may be a real number or animaginary number. Also, β may be a real number or an imaginary number.However, α is not 0 (zero). Also, β is not 0 (zero).

Alternatively, for the matrix Fp, it is conceivable to use any of thematrices from Formula (13) to Formula (20) below.

$\begin{matrix}{{Fp} = \begin{pmatrix}{\beta \times {\cos\theta}} & {\beta \times {\sin\theta}} \\{\beta \times {\sin\theta}} & {{- \beta} \times {\cos\theta}}\end{pmatrix}} & (13) \\{{Fp} = \begin{pmatrix}{\cos\theta} & {\sin\theta} \\{\sin\theta} & {- {\cos\theta}}\end{pmatrix}} & (14) \\{{Fp} = \begin{pmatrix}{\beta \times {\cos\theta}} & {{- \beta} \times {\sin\theta}} \\{\beta \times {\sin\theta}} & {\beta \times {\cos\theta}}\end{pmatrix}} & (15) \\{{Fp} = \begin{pmatrix}{\cos\theta} & {- {\sin\theta}} \\{\sin\theta} & {\cos\theta}\end{pmatrix}} & (16) \\{{Fp} = \begin{pmatrix}{\beta \times {\sin\theta}} & {{- \beta} \times {\cos\theta}} \\{\beta \times {\cos\theta}} & {\beta \times {\sin\theta}}\end{pmatrix}} & (17) \\{{Fp} = \begin{pmatrix}{\sin\theta} & {- {\cos\theta}} \\{\cos\theta} & {\sin\theta}\end{pmatrix}} & (18) \\{{Fp} = \begin{pmatrix}{\beta \times {\sin\theta}} & {\beta \times {\cos\theta}} \\{\beta \times {\cos\theta}} & {{- \beta} \times {\sin\theta}}\end{pmatrix}} & (19) \\{{Fp} = \begin{pmatrix}{\sin\theta} & {\theta\cos} \\{\theta\cos} & {- {\sin\theta}}\end{pmatrix}} & (20)\end{matrix}$Note that in Formula (13) to Formula (20), θ is a real number. Also, inFormula (13), Formula (15), Formula (17), and Formula (19), β may be areal number or an imaginary number. However, β is not 0 (zero).

Alternatively, for the matrix Fp, it is conceivable to use any of thematrices from Formula (21) to Formula (32) below.

$\begin{matrix}{{F{p(i)}} = \begin{pmatrix}{\beta \times e^{j{\theta_{11}{(i)}}}} & {\beta \times \alpha \times e^{j{({{\theta_{11}{(i)}} + \lambda})}}} \\{\beta \times \alpha \times e^{j{\theta_{21}{(i)}}}} & {\beta \times e^{j{({{\theta_{21}{(i)}} + \lambda + })}}}\end{pmatrix}} & (21) \\{{F{p(i)}} = {\frac{1}{\sqrt{\alpha^{2} + 1}}\begin{pmatrix}e^{{j\theta}_{11}{(i)}} & {\alpha \times e^{j{({{\theta_{11}{(i)}} + \lambda})}}} \\{\alpha \times e^{j{\theta_{21}{(i)}}}} & e^{j{({{\theta_{21}{(i)}} + \lambda + \pi})}}\end{pmatrix}}} & (22) \\{{F{p(i)}} = \begin{pmatrix}{\beta \times \alpha \times e^{j{\theta_{21}{(i)}}}} & {\beta \times e^{j{({{\theta_{21}{(i)}} + \lambda + })}}} \\{\beta \times e^{{j\theta}_{11}{(i)}}} & {\beta \times \alpha \times e^{j{({{\theta_{11}{(i)}} + \lambda})}}}\end{pmatrix}} & (23) \\{{F{p(i)}} = {\frac{1}{\sqrt{\alpha^{2} + 1}}\begin{pmatrix}{\alpha \times e^{j{\theta_{21}{(i)}}}} & e^{j{({{\theta_{21}{(i)}} + \lambda + })}} \\e^{j{\theta_{11}{(i)}}} & {\alpha \times e^{j{({{\theta_{11}{(i)}} + \lambda})}}}\end{pmatrix}}} & (24) \\{{F{p(i)}} = \begin{pmatrix}{\beta \times e^{j\theta_{11}}} & {\beta \times \alpha \times e^{j{({\theta_{11} + {\lambda{(i)}}})}}} \\{\beta \times \alpha \times e^{j\theta_{21}}} & {\beta \times e^{j{({\theta_{21} + {\lambda{(i)}} + })}}}\end{pmatrix}} & (25) \\{{F{p(i)}} = {\frac{1}{\sqrt{\alpha^{2} + 1}}\begin{pmatrix}e^{j\theta_{11}} & {\alpha \times e^{j{({\theta_{11} + {\lambda{(i)}}})}}} \\{\alpha \times e^{j\theta_{21}}} & e^{j{({\theta_{21} + {\lambda{(i)}} + })}}\end{pmatrix}}} & (26) \\{{{Fp}(i)} = \begin{pmatrix}{\beta \times \alpha \times e^{j\theta_{21}}} & {\beta \times e^{j{({\theta_{21} + {\lambda{(i)}} + })}}} \\{\beta \times e^{j\theta_{11}}} & {\beta \times \alpha \times e^{j{({\theta_{11} + {\lambda{(i)}}})}}}\end{pmatrix}} & (27) \\{{F{p(i)}} = {\frac{1}{\sqrt{\alpha^{2} + 1}}\begin{pmatrix}{\alpha \times e^{j\theta_{21}}} & e^{j{({\theta_{21} + {\lambda{(i)}} + })}} \\e^{j\theta_{11}} & {\alpha \times e^{j{({\theta_{11} + {\lambda{(i)}}})}}}\end{pmatrix}}} & (28) \\{{Fp} = \begin{pmatrix}{\beta \times e^{{j\theta}_{11}}} & {\beta \times \alpha \times e^{j{({\theta_{11} + \lambda})}}} \\{\beta \times \alpha \times e^{j\theta_{21}}} & {\beta \times e^{j{({\theta_{21} + \lambda + })}}}\end{pmatrix}} & (29) \\{{Fp} = {\frac{1}{\sqrt{\alpha^{2} + 1}}\begin{pmatrix}e^{j\theta_{11}} & {\alpha \times e^{j{({\theta_{11} + \lambda})}}} \\{\alpha \times e^{j\theta_{21}}} & e^{j{({\theta_{21} + \lambda + \pi})}}\end{pmatrix}}} & (30) \\{{Fp} = \begin{pmatrix}{\beta \times \alpha \times e^{j\theta_{21}}} & {\beta \times e^{j{({\theta_{21} + \lambda + })}}} \\{\beta \times e^{j\theta_{11}}} & {\beta \times \alpha \times e^{j{({\theta_{11} + \lambda})}}}\end{pmatrix}} & (31) \\{{Fp} = {\frac{1}{\sqrt{\alpha^{2} + 1}}\begin{pmatrix}{\alpha \times e^{j\theta_{21}}} & e^{j{({\theta_{21} + \lambda + \pi})}} \\e^{j\theta_{11}} & {\alpha \times e^{j{({\theta_{11} + \lambda})}}}\end{pmatrix}}} & (32)\end{matrix}$Herein, θ11(i), θ21(i), and λ(i) are functions of i (the symbol number),and are real values. For example, λ is a real, fixed value. Note that λmay also not be a fixed value. Also, α may be a real number or animaginary number. Also, β may be a real number or an imaginary number.However, α is not 0 (zero). Also, β is not 0 (zero). Also, θ11 and θ21are real numbers.

Alternatively, for the matrix Fp, it is conceivable to use any of thematrices from Formula (33) to Formula (36) below.

$\begin{matrix}{{Fp} = \begin{pmatrix}1 & 0 \\0 & 1\end{pmatrix}} & (33) \\{{Fp} = \begin{pmatrix}\beta & 0 \\0 & \beta\end{pmatrix}} & (34) \\{{Fp} = \begin{pmatrix}1 & 0 \\0 & {- 1}\end{pmatrix}} & (35) \\{{Fp} = \begin{pmatrix}\beta & 0 \\0 & {- \beta}\end{pmatrix}} & (36)\end{matrix}$Note that in Formula (34) and Formula (36), β may be a real number or animaginary number. However, β is not 0 (zero).

Note that even if a precoding matrix different from Formulas (5) to (36)above is used, it is still possible to carry out each embodiment.

Also, in the case of expressing the precoding matrix Fp like in Formula(33) or Formula (34), the weight combiner 303 in FIG. 3 does not performsignal processing on the mapped signals 301A and 301B, and insteadoutputs the mapped signal 301A as a weighted signal 304A, and outputsthe mapped signal 301B as a weighted signal 304B. In other words, theweight combiner 303 may also not exist, and in the case in which theweight combiner 303 exists, the weight combiner 303 may be controlled bythe control signal 300 to perform weight combining or not perform weightcombining.

The inserter 307A accepts the weighted signal 304A, a pilot symbolsignal (pa(t)) (351A), a preamble signal 352, a control informationsymbol signal 353, and the control signal 300 as input. On the basis ofinformation about the frame configuration included in the control signal300, the inserter 307A outputs a baseband signal 308A based on the frameconfiguration to the multiplexing signal processor 104.

Similarly, the inserter 307B accepts the phase-changed signal 306B, apilot symbol signal (pb(t)) (351B), the preamble signal 352, the controlinformation symbol signal 353, and the control signal 300 as input. Onthe basis of information about the frame configuration included in thecontrol signal 300, the inserter 307B outputs a baseband signal 308Bbased on the frame configuration to the phase changer 309B.

Note that the generation of control information for generating thecontrol information symbol signal 353 and the frame configuration in thetransmission apparatus used in the inserter 307B will be describedlater.

The phase changer 309B accepts the baseband signal 308B and the controlsignal 300 as input. The phase changer 309B changes the phase of thebaseband signal 308B on the basis of the control signal 300, and outputsa phase-changed signal 310B to the multiplexing signal processor 104.

The baseband signal 308B is taken to be a function of the symbol numberi, and is expressed as xp′(i). Thus, the phase-changed signal 310B(xp(i)) output from the phase changer 309B may be expressed asxp(i)=e^(j×ε(i))×xp′(i).

The operation of the phase changer 309B may be cyclic delay diversity(CDD) (cyclic shift diversity (CSD)) described in NPL 2 and NPL 3.Additionally, a characteristic of the phase changer 309B is that thephase change is executed on symbols existing in the frequency axisdirection. The phase changer 309B performs phase change on data symbols,pilot symbols, control information symbols, and the like.

Note that although FIG. 3 illustrates the signal processor 206 providedwith the phase changer 309B, the phase changer 309B may also not beincluded in the signal processor 206. Alternatively, even in the case inwhich the phase changer 309B is included in the signal processor 206,whether or not the phase changer 309B operates may be switched. In thecase in which the phase changer 309B is not included in the signalprocessor 206, or in the case in which the phase changer 309B does notoperate, the inserter 307B outputs the baseband signal 308B to themultiplexing signal processor 104 of FIG. 1. In this way, in FIG. 3, inthe case in which the phase changer 309B does not exist, or in the casein which the phase changer 309B does not operate, the baseband signal308B becomes the output signal to the multiplexing signal processor 104instead of the phase-changed signal 310B. Hereinafter, for the sake ofconvenience, the case in which the phase changer 309B does not operatewill be described.

Note that in the case in which the weight combining (precoding) processis executed using the (precoding) matrix Fp illustrated in Formula (33)or Formula (34), the weight combiner 303 does not perform signalprocessing for weight combining on the mapped signals 301A and 301B, andinstead outputs the mapped signal 301A as the weighted signal 304A, andoutputs the mapped signal 301B as the weighted signal 304B.

In this case, on the basis of the control signal 300, the weightcombiner 303 controls the switching between a process (i) and a process(ii), namely, (i) a process of performing signal processingcorresponding to weight combining to generate and output the weightedsignals 304A and 304B, and (ii) a process of not executing signalprocessing for weight combining, and instead outputting the mappedsignal 301A as the weighted signal 304A, and outputting the mappedsignal 301B as the weighted signal 304B.

Also, in the case in which the weight combining (precoding) process isexecuted by using only the (precoding) matrix Fp of Formula (33) orFormula (34), the signal processor 206 of FIG. 2 may also not beprovided with the weight combiner 303.

The above describes a case in which the mapper 204 of FIG. 2 generatesthe signals of two sequences when multi-stream transmission is selectedfor user #p. However, in the case in which single-stream transmission isselected for user #p, in FIG. 3, the weight combiner 303, the phasechanger 305B, and the inserter 307B may not operate, and the user #pmapped signal 301A may be input into the inserter 307A without beingweighted. Alternatively, in the case in which single-stream transmissionis selected, the user #p signal processor 102_p in FIG. 1 may not beprovided with the weight combiner 303, the phase changer 305B, and theinserter 307B among the configuration of FIG. 3.

Also, the above describes a case in which the mapper 204 of FIG. 2generates the signals of two sequences when multi-stream transmission isselected for user #p. However, the mapper 204 of FIG. 2 may alsogenerate the signals of three or more sequences when multi-streamtransmission is selected for user #p. In the case in which the mapper204 of FIG. 2 generates the signals of three or more sequences, theweight combiner 303 of FIG. 3 executes weight combining using aprecoding matrix that depends on the number of input signals, forexample, and outputs three or more weighted signals. Note that thenumber of signals input into the weight combiner 303 of FIG. 3 and thenumber of signals output from the weight combiner 303 do not have to bethe same. In other words, the precoding matrix used by the weightcombiner 303 does not have to be a square matrix.

Also, in the case in which the weight combiner 303 outputs three or moreweighted signals, the signal processor 102_p may change the phase of allor some of the three or more weighted signals. Alternatively, in thesignal processor 102_p, phase change does not have to be executed on allof the three or more weighted signals which are output.

FIG. 4 is a diagram illustrating a different example from FIG. 3 of theconfiguration of the signal processor 206 in FIG. 2. In FIG. 4, parts ofthe configuration which are similar to FIG. 3 are denoted with the samenumbers. Note that a description will be omitted herein for the parts ofthe configuration which are similar to FIG. 3.

The signal processor 206 of FIG. 4 is a configuration obtained by addinga coefficient multiplier 401A and a coefficient multiplier 401B to thesignal processor 206 of FIG. 3.

The coefficient multiplier 401A accepts the mapped signal 301A (sp1(i))and the control signal 300 as input. On the basis of the control signal300, the coefficient multiplier 401A multiplies the mapped signal 301A(sp1(i)) by a coefficient, and outputs a coefficient-multiplied signal402A to the weight combiner 303. Note that, provided that thecoefficient is up, the coefficient-multiplied signal 402A is expressedas up×sp1(i). Herein, up may be a real number or a complex number.However, up is not 0 (zero). Note that in the case of up=1, thecoefficient multiplier 401A does not multiply the mapped signal 301A(sp1(i)) by the coefficient, and outputs the mapped signal 301A (sp1(i))as the coefficient-multiplied signal 402A.

Similarly, the coefficient multiplier 401B accepts the mapped signal301B (sp2(i)) and the control signal 300 as input. On the basis of thecontrol signal 300, the coefficient multiplier 401B multiplies themapped signal 301B (sp2(i)) by a coefficient, and outputs acoefficient-multiplied signal 402B to the weight combiner 303. Notethat, provided that the coefficient is vp, the coefficient-multipliedsignal 402B is expressed as vp×sp2(i). Herein, vp may be a real numberor a complex number. However, vp is not 0 (zero). Note that in the caseof vp=1, the coefficient multiplier 401B does not multiply the mappedsignal 301B (sp2(i)) by the coefficient, and outputs the mapped signal301B (sp2(i)) as the coefficient-multiplied signal 402B.

In FIG. 4, the weighted signal 304A (zp1(i)) output from the weightcombiner 303 and the phase-changed signal 306B (zp2(i)) output from thephase changer 305B are expressed by the following Formula (37) using thecoefficient up of the coefficient multiplier 401A, the coefficient vp ofthe coefficient multiplier 401B, and Formula (3).

$\begin{matrix}\begin{matrix}{\begin{pmatrix}{zp1(i)} \\{zp2(i)}\end{pmatrix} = {\begin{pmatrix}1 & 0 \\0 & {y{p(i)}}\end{pmatrix}{{Fp}\begin{pmatrix}{up} & 0 \\0 & {vp}\end{pmatrix}}\begin{pmatrix}{sp1(i)} \\{sp2(i)}\end{pmatrix}}} \\{= {\begin{pmatrix}1 & 0 \\0 & {{yp}(i)}\end{pmatrix}\begin{pmatrix}a & b \\c & d\end{pmatrix}\begin{pmatrix}{up} & 0 \\0 & {vp}\end{pmatrix}\begin{pmatrix}{{sp}\; 1(i)} \\{sp2(i)}\end{pmatrix}}} \\{= {\begin{pmatrix}1 & 0 \\0 & e^{j \times {{\delta p}{(i)}}}\end{pmatrix}\begin{pmatrix}a & b \\c & d\end{pmatrix}\begin{pmatrix}{up} & 0 \\0 & {vp}\end{pmatrix}\begin{pmatrix}{sp1(i)} \\{sp2(i)}\end{pmatrix}}}\end{matrix} & (37)\end{matrix}$Note that examples of the (precoding) matrix Fp are Formulas (5) to(36), as described already. Also, an example of the phase change valueyp(i) is illustrated in Formula (2). However, the (precoding) matrix Fpand the phase change value yp(i) are not limited to the above.

FIGS. 1 to 4 and Formulas (1) to (37) are cited as an example todescribe a method by which the user #p signal processor 102_p generatessymbols (for example, zp1(i), zp2(i)). The generated symbols may bearranged in the time axis direction. Also, in the case of using amulti-carrier scheme such as orthogonal frequency-division multiplexing(OFDM), the generated symbols may also be arranged in the frequency axisdirection, or in the time-frequency directions. Also, the generatedsymbols may be interleaved (that is, the symbols may be sorted) andarranged in the time axis direction, the frequency axis direction, orthe time-frequency axis directions.

Symbol arranging is executed in the user #p signal processor 102_p bythe error-correcting coder 202 and/or the mapper 204 illustrated in FIG.2, for example.

Note that symbol arrangement method will be described later.

The transmission apparatus illustrated in FIG. 1 transmits zp1(i) andzp2(i) having the same symbol number i using identical times andidentical frequencies (identical frequency bands).

The user #1 baseband signal 103_1_1 in FIG. 1 becomes zp1(i) whensetting p=1, and the user #1 baseband signal 103_1_2 becomes zp2(i) whensetting p=1. Similarly, the user #2 baseband signal 103_2_1 becomeszp1(i) when setting p=2, and the user #2 baseband signal 103_2_2 becomeszp2(i) when setting p=2. Similarly, the user #M baseband signal 103_M_1becomes zp1(i) when setting p=M, and the user #M baseband signal 103_M_2becomes zp2(i) when setting p=M.

Note that the user #1 signal processor 102_1 uses Formula (3) or Formula(37) to generate the user #1 baseband signal 103_1_1 and the user #1baseband signal 103_1_2. Similarly, the user #2 signal processor 102_2uses Formula (3) or Formula (37) to generate the user #2 baseband signal103_2_1 and the user #2 baseband signal 103_2_2. Similarly, the user #Msignal processor 102_M generates the user #M baseband signal 103_M_1 andthe user #M baseband signal 103_M_2.

At this time, in the case of applying precoding and phase change togenerate the user #p baseband signal 103_p_1 and the user #p basebandsignal 103_p_2, the precoding matrix Fp made up of a, b, c, and d inFormula (3) and Formula (37) and/or the phase change value yp(i) are setdepending on the value of p.

In other words, the precoding matrix Fp and/or the phase change valueyp(i) used in the user #p signal processor 102_p are set respectivelydepending on the value of p, or in other words, for each user.Information for setting the precoding matrix Fp and/or the phase changevalue yp(i) is included in the control signal.

However, precoding and phase change may not be applied to all from theuser #1 signal processor 102_1 to the user #M signal processor 102_M inFIG. 1. For example, a signal processor for which phase change is notexecuted may exist among the user #1 signal processor 102_1 to the user#M signal processor 102_M. Also, a signal processor that generates asingle baseband signal (the baseband signal of a single stream) mayexist among the user #1 signal processor 102_1 to the user #M signalprocessor 102_M.

As above, in the user #1 signal processor 102_1 to the user #M signalprocessor 102_M in FIG. 1, as described in the present embodiment, inthe case of executing precoding and phase change, in an environment inwhich direct waves are dominant, there is an increased possibility ofbeing able to avoid falling into a steady reception state, and anadvantageous effect of improved received signal quality of data at aterminal may be obtained. Additionally, like in FIG. 1, by transmittingthe modulated signals of multiple users, an advantageous effect ofimproved data transmission efficiency in the transmission apparatus ofFIG. 1 may also be obtained.

Note that in the case in which the control signal 300 includesinformation indicating that “the phase changer 305B does not executephase change”, the phase changer 305B does not execute phase change, orin other words, the phase changer 305B does not change the phase of theinput weighted signal 304B, and outputs the weighted signal 304B as306B.

<Example of Multiplexing Signal Process of Multiplexing Signal Processor104>

The multiplexing signal process (weight combining process) in themultiplexing signal processor 104 of FIG. 1 will be describedspecifically.

Assume that the user #p first baseband signal 103_p_1 and the user #psecond baseband signal 103_p_2 output by the user #p signal processor102_p (where p is an integer from 1 to M) in FIG. 1 are expressed aszp1(i) and zp2(i) on the basis of Formula (3). Herein, i is taken to bethe symbol number. For example, i is treated as being an integer equalto 0 or greater. At this time, assume that the signals b{2p−1}(i) andb{2p}(i) are expressed as in the following Formulas (38) and (39).b{2p−1}(i)=zp1(i)  (38)b{2p}(i)=zp2(i)  (39)

For example, the user #1 first baseband signal 103_1_1 and the user #1second baseband signal 103_1_2 are expressed as b{1}(i) and b{2}(i),respectively. In other words, in the case in which each from the user #1signal processor 102_1 to the user #M signal processor 102_M outputs twosignals, the output signals are expressed as b{1}(i) to b{2M}(i).

Note that in the case of transmitting a single stream (single modulatedsignal), either zp1(i) or zp2(i) may be zero.

In addition, the output of the multiplexing signal processor 104, namelythe multiplexed signal $1 baseband signal 105_1 to the multiplexedsignal $N baseband signal 105_N, are denoted v1(i) to vN(i),respectively. In other words, the multiplexed signal $n baseband signal105_n becomes vn(i) (where n is an integer from 1 to N). At this time,vn(i) may be expressed by the following Formula (40).

$\begin{matrix}{{{vn}(i)} = {\underset{k = 1}{\sum\limits^{2M}}{\Omega\left\{ n \right\}\left\{ k \right\} \times b\left\{ k \right\}(i)}}} & (40)\end{matrix}$At this time, Ω{n}{k} is the weighted coefficient of multiplexing, andmay be defined as a complex number. Thus, Ω{n}{k} may be a real number.Additionally, Ω{n}{k} is decided by feedback information of eachterminal.

Note that in the present embodiment, a case in which the user #p signalprocessor 102_p in FIG. 1 outputs one or two modulated signals isdescribed as an example, but the configuration is not limited thereto,and the user #p signal processor 102_p may also output three or moremodulated signals. In this case, the process of the multiplexing signalprocessor 104 must be expressed by a different formula from Formula(40).

<Example of Configuration of Radio Section>

As described earlier, the radio section $1 (106_1) to the radio section$N (106_N) in FIG. 1 execute processes such as frequency conversion andamplification on a signal input into each, and generate a transmissionsignal. At this time, in the radio section $1 (106_1) to the radiosection $N (106_N), either a single-carrier scheme or a multi-carrierscheme such as orthogonal frequency-division multiplexing (OFDM) may beused. In the following, a radio section $n (106_n) in which OFDM is usedwill be described as an example.

FIG. 5 is a diagram illustrating an example of a configuration of theradio section $n (106_n) in which OFDM is used. The radio section $n(106_n) is provided with a serial-parallel converter 502, an inverseFourier transform section 504, and a processor 506.

The serial-parallel converter 502 accepts a signal 501 and a controlsignal 500 as input. On the basis of the control signal 500, theserial-parallel converter 502 executes serial-parallel conversion on theinput signal 501, and outputs a serial-parallel converted signal 503 tothe inverse Fourier transform section 504. Note that the signal 501corresponds to the multiplexed signal $n baseband signal 105_n in FIG.1, and the control signal 500 corresponds to the control signal 100 inFIG. 1.

The inverse Fourier transform section 504 accepts the serial-parallelconverted signal 503 and the control signal 500 as input. On the basisof the control signal 500, the inverse Fourier transform section 504performs an inverse Fourier transform (for example, the inverse fastFourier transform (IFFT)), and outputs an inverse Fourier transformedsignal 505 to the processor 506.

The processor 506 accepts the inverse Fourier transformed signal 505 andthe control signal 500 as input. On the basis of the control signal 500,the processor 506 performs processes such as frequency conversion andamplification, and outputs a modulated signal 507 to the antenna section$n (108_n). The modulated signal 507 output from the processor 506corresponds to the transmission signal 107_n in FIG. 1.

<Example of Configuration of Antenna Section>

FIG. 6 is a diagram illustrating an example of the configuration of theantenna sections (antenna section $1 (108_1) to antenna section $N(108_N)) in FIG. 1. Note that the configuration in FIG. 6 is an examplein which the antenna section $1 (108_1) to the antenna section $N(108_N) are configured with four antennas. An antenna section isprovided with a distributor 902, multipliers 904_1 to 904_4, andantennas 906_1 to 906_4.

The distributor 902 accepts a transmission signal 901 as input. Thedistributor 902 distributes the transmission signal 901, and outputstransmission signals 903_1, 903_2, 903_3, and 903_4 to the correspondingmultipliers (multiplier 904_1 to multiplier 904_4).

When the antenna section $1 (108_1) in FIG. 1 has the configuration ofFIG. 6, the transmission signal 901 corresponds to the transmissionsignal 107_1 in FIG. 1. Also, when the antenna section $2 (108_2) inFIG. 1 has the configuration of FIG. 6, the transmission signal 901corresponds to the transmission signal 107_2 in FIG. 1. When the antennasection $N (108_N) in FIG. 1 has the configuration of FIG. 6, thetransmission signal 901 corresponds to the transmission signal 107_N inFIG. 1.

The multiplier 904_1 accepts the transmission signal 903_1 and a controlsignal 900 as input. On the basis of information about a multiplicationcoefficient included in the control signal 900, the multiplier 904_1multiplies the transmission signal 903_1 by the multiplicationcoefficient, and outputs a multiplied signal 905_1 to the antenna 906_1.The multiplied signal 905_1 is output from the antenna 906_1 as a radiowave.

Provided that the transmission signal 903_1 is Tx1(t) (where t is time),and the multiplication coefficient is W1, the multiplied signal 905_1 isexpressed as Tx1(t)×W1. Note that W1 may be defined as a complex number,and consequently, may also be a real number.

The multiplier 904_2 accepts the transmission signal 903_2 and thecontrol signal 900 as input. On the basis of information about amultiplication coefficient included in the control signal 900, themultiplier 904_2 multiplies the transmission signal 903_2 by themultiplication coefficient, and outputs a multiplied signal 905_2 to theantenna 906_2. The multiplied signal 905_2 is output from the antenna906_2 as a radio wave.

Provided that the transmission signal 903_2 is Tx2(t), and themultiplication coefficient is W2, the multiplied signal 905_2 isexpressed as Tx2(t)×W2. Note that W2 may be defined as a complex number,and consequently, may also be a real number.

The multiplier 904_3 accepts the transmission signal 903_3 and thecontrol signal 900 as input. On the basis of information about amultiplication coefficient included in the control signal 900, themultiplier 904_3 multiplies the transmission signal 903_3 by themultiplication coefficient, and outputs a multiplied signal 905_3 to theantenna 906_3. The multiplied signal 905_3 is output from the antenna906_3 as a radio wave.

Provided that the transmission signal 903_3 is Tx3(t), and themultiplication coefficient is W3, the multiplied signal 905_3 isexpressed as Tx3(t)×W3. Note that W3 may be defined as a complex number,and consequently, may also be a real number.

The multiplier 904_4 accepts the transmission signal 903_4 and thecontrol signal 900 as input. On the basis of information about amultiplication coefficient included in the control signal 900, themultiplier 904_4 multiplies the transmission signal 903_4 by themultiplication coefficient, and outputs a multiplied signal 905_4 to theantenna 906_4. The multiplied signal 905_4 is output from the antenna906_4 as a radio wave.

Provided that the transmission signal 903_4 is Tx4(t), and themultiplication coefficient is W4, the multiplied signal 905_4 isexpressed as Tx4(t)×W4. Note that W4 may be defined as a complex number,and consequently, may also be a real number.

Note that “the absolute value of W1, the absolute value of W2, theabsolute value of W3, and the absolute value of W4 may be equal”. Thiscase corresponds to executing a phase change. Obviously, the absolutevalue of W1, the absolute value of W2, the absolute value of W3, and theabsolute value of W4 may also not be equal.

Also, in FIG. 6, an example is described in which each antenna sectionis configured with four antennas (and four multipliers), but the numberof antennas is not limited to four, and it is sufficient for eachantenna section to include one or more antennas.

Also, the antenna section $1 (108_1) to the antenna section $N (108_N)do not have to be configured like in FIG. 6, and as described earlier,do not have to accept the control signal 100 as input. For example, eachfrom the antenna section $1 (108_1) to the antenna section $N (108_N) inFIG. 1 may be configured to include a single antenna or multipleantennas.

<Generation of Control Information>

FIG. 7 is a diagram illustrating an example of a configuration of aportion related to control information generation for generating thecontrol information symbol signal 353 in FIGS. 3 and 4.

A control information mapper 802 accepts control information-relateddata 801 and a control signal 800 as input. The control informationmapper 802 uses a modulation scheme based on the control signal 800 tomap the control information-related data 801, and outputs a controlinformation mapped signal 803. Note that the control information mappedsignal 803 corresponds to the control information symbol signal 353 inFIGS. 3 and 4.

<First Example of Frame Configuration in Transmission Apparatus>

Next, the frame configuration in the transmission apparatus will bedescribed. The frame configuration illustrates the arrangement of datasymbols, pilot symbols, and other symbols to be transmitted. Informationabout the frame configuration is included in the control signal 300 (seeFIGS. 3 and 4). Additionally, the inserter 307A and the inserter 307Billustrated in FIGS. 3 and 4 respectively generate the baseband signal308A and the baseband signal 308B based on the frame configuration.

The following takes, as an example, a case in which a multi-carriertransmission scheme such as OFDM is used, and in the user #p signalprocessor 102_p, the inserter 307A outputs the user #p first basebandsignal 103_p_1 as the baseband signal 308A, and the baseband signal 308Boutputs the user #p second baseband signal 103_p_2 as the basebandsignal 308B. Additionally, the frame configuration in this case will bedescribed by taking the user #p first baseband signal 103_p_1 and theuser #p second baseband signal 103_p_2 as an example.

FIG. 8 is a diagram illustrating an example of the frame configurationof the user #p first baseband signal 103_p_1. In FIG. 8, the horizontalaxis indicates frequency (carrier), while the vertical axis indicatestime. Since a multi-carrier transmission scheme such as OFDM is used,symbols exist in the carrier direction. FIG. 8 illustrates, as oneexample, symbols from carrier 1 to carrier 36. Also, FIG. 8 illustratessymbols from time 1 to time 11.

In FIG. 8, 601 illustrates pilot symbols (the pilot symbol signal 351A(corresponding to pa(t)) in FIGS. 3 and 4), 602 illustrates datasymbols, and 603 illustrates other symbols. At this time, the pilotsymbols are phase-shift keying (PSK) symbols, for example, and aresymbols by which the reception apparatus that receives the frameexecutes channel estimation (estimation of channel variation) andestimation of the frequency offset/phase variation. For example, thetransmission apparatus in FIG. 1 and the reception apparatus thatreceives a signal with the frame configuration of FIG. 8 preferablyshare the pilot symbol transmission method in common.

Meanwhile, the user #p mapped signal 205_1 is designated “stream #1”,and the user #p mapped signal 205_2 is designated “stream #2”. Note thatthe same also applies to the description hereinafter.

The data symbols 602 are symbols corresponding to the data symbolsincluded in the baseband signal 207_A generated in FIG. 2. Consequently,the data symbols 602 are any of “symbols including both the symbols of‘stream #1’ and the symbols of ‘stream #2’”, or “the symbols of ‘stream#1’”, or “the symbols of ‘stream #2’”. This is decided by theconfiguration of the precoding matrix used by the weight combiner 303 inFIG. 3. In other words, the data symbols 602 correspond to the weightedsignal 304A (zp1(i)).

The other symbols 603 are taken to be symbols corresponding to thepreamble signal 352 and the control information symbol signal 353 inFIGS. 3 and 4. However, the other symbols may also include symbols otherthan preamble and control information symbols. At this time, thepreamble may transmit data (for control), or includes symbols for signaldetection, symbols for executing frequency synchronization/timesynchronization, symbols for channel estimation (symbols for estimatingchannel variation), and the like. Additionally, the control informationsymbols are symbols including control information by which the receptionapparatus receiving the frame in FIG. 8 achieves the demodulation anddecoding of the data symbols.

For example, carrier 1 to carrier 36 from time 1 to time 4 in FIG. 8become the other symbols 603. Additionally, carrier 1 to carrier 11 attime 5 become the data symbols 602. In the following, carrier 12 at time5 becomes a pilot symbol 601, cater 13 to carrier 23 at time 5 becomedata symbols 602, carrier 24 at time 5 becomes a pilot symbol 601,carrier 1 and carrier 2 at time 6 become data symbols 602, carrier 3 attime 6 becomes a pilot symbol 601, carrier 30 at time 11 becomes a pilotsymbol 601, and carrier 31 to carrier 36 at time 11 become data symbols602.

FIG. 9 is a diagram illustrating an example of the frame configurationof the user #p second baseband signal 103_p_2. In FIG. 9, the horizontalaxis indicates frequency (carrier), while the vertical axis indicatestime. Since a multi-carrier transmission scheme such as OFDM is used,symbols exist in the carrier direction. FIG. 9 illustrates, as oneexample, symbols from carrier 1 to carrier 36. Also, FIG. 9 illustratessymbols from time 1 to time 11.

In FIG. 9, 701 illustrates pilot symbols (the pilot symbol signal 351B(corresponding to pb(t)) in FIGS. 3 and 4), 702 illustrates datasymbols, and 703 illustrates other symbols. At this time, the pilotsymbols are PSK symbols, for example, and are symbols by which thereception apparatus that receives the frame executes channel estimation(estimation of channel variation) and estimation of the frequencyoffset/phase variation. For example, the transmission apparatus in FIG.1 and the reception apparatus that receives a signal with the frameconfiguration of FIG. 9 preferably share the pilot symbol transmissionmethod in common.

The data symbols 702 are symbols corresponding to the data symbolsincluded in the baseband signal 207_B generated in FIG. 2. Consequently,the data symbols 702 are the symbols of any of the three possibilitiesof “symbols including both the symbols of ‘stream #1’ and the symbols of‘stream #2’”, “the symbols of ‘stream #1’”, and “the symbols of ‘stream#2’”. Which symbols among the three possibilities become the datasymbols 702 is decided by the configuration of the precoding matrix usedby the weight combiner 303 in FIG. 3. In other words, the data symbols702 correspond to the phase-changed signal 306B (zp2(i)).

The other symbols 703 are taken to be symbols corresponding to thepreamble signal 352 and the control information symbol signal 353 inFIGS. 3 and 4. However, the other symbols may also include symbols otherthan preamble and control information symbols. At this time, thepreamble may transmit data (for control), or includes symbols for signaldetection, symbols for executing frequency synchronization/timesynchronization, symbols for channel estimation (symbols for estimatingchannel variation), and the like. Additionally, the control informationsymbols are symbols including control information by which the receptionapparatus receiving the frame in FIG. 9 achieves the demodulation anddecoding of the data symbols.

For example, carrier 1 to carrier 36 from time 1 to time 4 in FIG. 9become the other symbols 703. Additionally, carrier 1 to carrier 11 attime 5 become the data symbols 702. In the following, carrier 12 at time5 becomes a pilot symbol 701, carrier 13 to carrier 23 at time 5 becomedata symbols 702, carrier 24 at time 5 becomes a pilot symbol 701,carrier 1 and carrier 2 at time 6 become data symbols 702, carrier 3 attime 6 becomes a pilot symbol 701, carrier 30 at time 11 becomes a pilotsymbol 701, and carrier 31 to carrier 36 at time 11 become data symbols702.

When a symbol exists at carrier A, time B in FIG. 8, and a symbol existsat carrier A, time B in FIG. 9, the symbol at carrier A, time B in FIG.8 and the symbol at carrier A, time B in FIG. 9 are transmitted atidentical times and identical frequencies. Note that the frameconfiguration is not limited to FIGS. 8 and 9, and that FIGS. 8 and 9are merely examples of the frame configuration.

Additionally, the other symbols 603 and 703 in FIGS. 8 and 9 are symbolscorresponding to “the preamble signal 352 and the control symbols 353 inFIGS. 3 and 4”. Consequently, in the case in which the other symbols 703in FIG. 9 at identical times and identical frequencies (identicalcarriers) as the other symbols 603 in FIG. 8 are transmitting controlinformation, identical data (identical control information) is beingtransmitted.

Note that although the reception apparatus is expecting to receive theframe in FIG. 8 and the frame in FIG. 9 at the same time, the receptionapparatus is able to obtain the data transmitted by the transmissionapparatus even if only the frame in FIG. 8 or only the frame in FIG. 9is received.

Additionally, in the user #1 signal processor 102_1 of FIG. 1, in thecase of outputting the first baseband signal 103_1_1 and the secondbaseband signal 103_1_2, the first baseband signal 103_1_1 and thesecond baseband signal 103_1_2 take the frame configurations of FIG. 8and FIG. 9, respectively. Similarly, in the user #2 signal processor102_2 of FIG. 1, in the case of outputting the first baseband signal103_2_1 and the second baseband signal 103_2_2, the first basebandsignal 103_2_1 and the second baseband signal 103_2_2 take the frameconfigurations of FIG. 8 and FIG. 9, respectively. Similarly, in theuser #M signal processor 102_M of FIG. 1, in the case of outputting thefirst baseband signal 103_M_1 and the second baseband signal 103_M_2,the first baseband signal 103_M_1 and the second baseband signal 103_M_2take the frame configurations of FIG. 8 and FIG. 9, respectively.

<Second Example of Frame Configuration in Transmission Apparatus>

In FIGS. 8 and 9, a frame configuration is described for the case inwhich a multi-carrier transmission scheme such as OFDM is used. Herein,a frame configuration in a transmission apparatus will be described forthe case in which a single-carrier scheme is used.

FIG. 10 is a diagram illustrating a different example of the frameconfiguration of the user #p first baseband signal 103_p_1. In FIG. 10,the horizontal axis is time. FIG. 10 is different from FIG. 8 in thatthe frame configuration in FIG. 10 is an example of the frameconfiguration for a single-carrier scheme, and symbols exist in the timedirection. Additionally, in FIG. 10, symbols from time t1 to t22 areillustrated.

A preamble 1001 in FIG. 10 corresponds to the preamble signal 352 inFIGS. 3 and 4. At this time, the preamble may transmit data (forcontrol), or may include symbols for signal detection, symbols forexecuting frequency synchronization/time synchronization, symbols forexecuting channel estimation (symbols for estimating channel variation),and the like.

A control information symbol 1002 in FIG. 10 is a symbol correspondingto the control information symbol signal 353 in FIGS. 3 and 4, and is asymbol including control information by which a reception apparatus thatreceives a signal with the frame configuration of FIG. 10 achievesdemodulation and decoding of the data symbols.

A pilot symbol 1004 in FIG. 10 is a symbol corresponding to the pilotsignal 351A (pa(t)) in FIGS. 3 and 4. The pilot symbol 1004 is a PSKsymbol, for example, and is a symbol by which the reception apparatusthat receives the frame executes channel estimation (estimation ofchannel variation) and estimation of the frequency offset/estimation ofphase variation. For example, the transmission apparatus in FIG. 1 andthe reception apparatus that receives a signal with the frameconfiguration of FIG. 10 preferably share the pilot symbol transmissionmethod in common.

In FIG. 10, 1003 are data symbols for transmitting data.

The user #p mapped signal 205_1 is designated “stream #1”, and the user#p mapped signal 205_2 is designated “stream #2”.

The data symbols 1003 are symbols corresponding to the data symbolsincluded in the baseband signal 206_A generated in FIG. 2. Consequently,the data symbols 1003 are the symbols of any of the three possibilitiesof “symbols including both the symbols of ‘stream #1’ and the symbols of‘stream #2’”, “the symbols of ‘stream #1’”, and “the symbols of ‘stream#2’”. Which symbols among the three possibilities become the datasymbols 702 is decided by the configuration of the precoding matrix usedby the weight combiner 303 in FIG. 3. In other words, the data symbols1003 correspond to the weighted signal 304A (zp1(i)).

For example, suppose that the transmission apparatus transmits thepreamble 1001 at time t1 in FIG. 10, transmits the control informationsymbol 1002 at time t2, transmits the data symbols 1003 from time t3 tot11, transmits the pilot symbol 1004 at time t12, transmits the datasymbols 1003 from time t13 to t21, and transmits the pilot symbol 1004at time t22.

Note that, although not illustrated in FIG. 10, the frame may alsoinclude symbols other than the preamble, the control information symbol,the data symbols, and the pilot symbol. Also, the frame does not have toinclude all of the preamble, the control information symbol, and thepilot symbol.

FIG. 11 is a diagram illustrating a different example of the frameconfiguration of the user #p second baseband signal 103_p_2. In FIG. 11,the horizontal axis is time. FIG. 11 is different from FIG. 9 in thatthe frame configuration in FIG. 11 is an example of the frameconfiguration for a single-carrier scheme, and symbols exist in the timedirection. Additionally, in FIG. 11, symbols from time t1 to t22 areillustrated.

A preamble 1101 in FIG. 11 corresponds to the preamble signal 352 inFIGS. 3 and 4. At this time, the preamble may transmit data (forcontrol), or may include symbols for signal detection, symbols forexecuting frequency synchronization/time synchronization, symbols forexecuting channel estimation (symbols for estimating channel variation),and the like.

A control information symbol 1102 in FIG. 11 is a symbol correspondingto the control information symbol signal 353 in FIGS. 3 and 4, and is asymbol including control information by which a reception apparatus thatreceives a signal with the frame configuration of FIG. 11 achievesdemodulation and decoding of the data symbols.

A pilot symbol 1104 in FIG. 11 is a symbol corresponding to the pilotsignal 351B (pb(t)) in FIGS. 3 and 4. The pilot symbol 1104 is a PSKsymbol, for example, and is a symbol by which the reception apparatusthat receives the frame executes channel estimation (estimation ofchannel variation) and estimation of the frequency offset/estimation ofphase variation. For example, the transmission apparatus in FIG. 1 andthe reception apparatus that receives a signal with the frameconfiguration of FIG. 11 preferably share the pilot symbol transmissionmethod in common.

In FIG. 11, 1103 are data symbols for transmitting data.

The user #p mapped signal 205_1 is designated “stream #1”, and the user#p mapped signal 205_2 is designated “stream #2”.

The data symbols 1103 are symbols corresponding to the data symbolsincluded in the baseband signal 206_B generated in FIG. 2. Consequently,the data symbols 1103 are the symbols of any of the three possibilitiesof “symbols including both the symbols of ‘stream #1’ and the symbols of‘stream #2’”, “the symbols of ‘stream #1’”, and “the symbols of ‘stream#2’”. Which symbols among the three possibilities become the datasymbols 702 is decided by the configuration of the precoding matrix usedby the weight combiner 303 in FIG. 3. In other words, the data symbols1103 correspond to the phase-changed signal 306B (zp2(i)).

For example, suppose that the transmission apparatus transmits thepreamble 1101 at time t1 in FIG. 11, transmits the control informationsymbol 1102 at time t2, transmits the data symbols 1103 from time t3 tot11, transmits the pilot symbol 1104 at time t12, transmits the datasymbols 1103 from time t13 to t21, and transmits the pilot symbol 1104at time t22.

Note that, although not illustrated in FIG. 11, the frame may alsoinclude symbols other than the preamble, the control information symbol,the data symbols, and the pilot symbol. Also, the frame does not have toinclude all of the preamble, the control information symbol, and thepilot symbol.

When a symbol exists at time tz in FIG. 10, and a symbol exists at timetz in FIG. 11 (where z is an integer equal to 1 or greater), the symbolat time tz in FIG. 10 and the symbol at time tz in FIG. 11 aretransmitted at identical times and identical frequencies. For example,the data symbol at time t3 in FIG. 10 and the data symbol at time t3 inFIG. 11 are transmitted at identical times and identical frequencies.Note that the frame configuration is not limited to FIGS. 10 and 11, andthat FIGS. 10 and 11 are merely examples of the frame configuration.

Additionally, a method in which identical data (identical controlinformation) is transmitted in the preamble and the control informationsymbol in FIGS. 10 and 11 is also possible.

Note that although the reception apparatus is expecting to receive theframe in FIG. 10 and the frame in FIG. 11 at the same time, thereception apparatus is able to obtain the data transmitted by thetransmission apparatus even if only the frame in FIG. 10 or only theframe in FIG. 11 is received.

Additionally, in the user #1 signal processor 102_1 of FIG. 1, in thecase of outputting the first baseband signal 103_1_1 and the secondbaseband signal 103_1_2, the first baseband signal 103_1_1 and thesecond baseband signal 103_1_2 take the frame configurations of FIG. 10and FIG. 11, respectively. Similarly, in the user #2 signal processor102_2 of FIG. 1, in the case of outputting the first baseband signal103_2_1 and the second baseband signal 103_2_2, the first basebandsignal 103_2_1 and the second baseband signal 103_2_2 take the frameconfigurations of FIG. 10 and FIG. 11, respectively. Similarly, in theuser #M signal processor 102_M of FIG. 1, in the case of outputting thefirst baseband signal 103_M_1 and the second baseband signal 103_M_2,the first baseband signal 103_M_1 and the second baseband signal 103_M_2take the frame configurations of FIG. 10 and FIG. 11, respectively.

<Symbol Arrangement Method>

Next, the symbol arrangement method in the present embodiment will bedescribed. Symbols are sorted on the frequency axis and/or the time axisby the interleaver. For example, symbol arranging is executed in theuser #p signal processor 102_p by the error-correcting coder 202 and/orthe mapper 204 illustrated in FIG. 2, for example.

FIG. 12 is a diagram illustrating an example of a symbol arrangementmethod with respect to the time axis of the weighted signal 304A(zp1(i)) and the phase-changed signal 306B (zp2(i)).

In FIG. 12, symbols are denoted as zpq(0). At this time, q is 1 or 2.Thus, zpq(0) in FIG. 12 expresses “in zp1(i) and zp2(i), zp1(0) andzp2(0) when the symbol number i=0”. Similarly, zpq(1) expresses “inzp1(i) and zp2(i), zp1(1) and zp2(1) when the symbol number i=1”. Inother words, zpq(X) expresses “in zp1(i) and zp2(i), zp1(X) and zp2(X)when the symbol number i=X”. Note that the same applies to FIGS. 13, 14,and 15.

In the example of FIG. 12, the symbol zpq(0) with the symbol number i=0is arranged at time 0, the symbol zpq(1) with the symbol number i=1 isarranged at time 1, the symbol zpq(2) with the symbol number i=2 isarranged at time 2, and the symbol zpq(3) with the symbol number i=3 isarranged at time 3. In this way, the symbols in the weighted signal 304A(zp1(i)) and the phase-changed signal 306B (zp2(i)) are arranged withrespect to the time axis. However, FIG. 12 is an example, and therelationship between symbol number and time is not limited thereto.

FIG. 13 is a diagram illustrating an example of a symbol arrangementmethod with respect to the frequency axis of the weighted signal 304A(zp1(i)) and the phase-changed signal 306B (zp2(i)).

In the example of FIG. 13, the symbol zpq(0) with the symbol number i=0is arranged at carrier 0, the symbol zpq(1) with the symbol number i=1is arranged at carrier 1, the symbol zpq(2) with the symbol number i=2is arranged at carrier 2, and the symbol zpq(3) with the symbol numberi=3 is arranged at carrier 3. In this way, symbols are arranged withrespect to the frequency axis of the weighted signal 304A (zp1(i)) andthe phase-changed signal 306B (zp2(i)). However, FIG. 13 is an example,and the relationship between symbol number and frequency is not limitedthereto.

FIG. 14 is a diagram illustrating an example of symbol arrangement withrespect to the time/frequency axes of the weighted signal 304A (zp1(i))and the phase-changed signal 306B (zp2(i)).

In the example of FIG. 14, the symbol zpq(0) with the symbol number i=0is arranged at time 0 and carrier 0, the symbol zpq(1) with the symbolnumber i=1 is arranged at time 0 and carrier 1, the symbol zpq(2) withthe symbol number i=2 is arranged at time 1 and carrier 0, and thesymbol zpq(3) with the symbol number i=3 is arranged at time 1 andcarrier 1. In this way, symbols are arranged with respect to the timeand frequency axes of the weighted signal 304A (zp1(i)) and thephase-changed signal 306B (zp2(i)). However, FIG. 14 is an example, andthe relationship between symbol number and time/frequency is not limitedthereto.

FIG. 15 is a diagram illustrating an example of a symbol arrangementwith respect to the time axis of the weighted signal 304A (zp1(i)) andthe phase-changed signal 306B (zp2(i)).

In the example of FIG. 15, the symbol zpq(0) with the symbol number i=0is arranged at time 0, the symbol zpq(1) with the symbol number i=1 isarranged at time 16, the symbol zpq(2) with the symbol number i=2 isarranged at time 12, and the symbol zpq(3) with the symbol number i=3 isarranged at time 5. In this way, symbols are arranged with respect tothe time axis of the weighted signal 304A (zp1(i)) and the phase-changedsignal 306B (zp2(i)) in FIG. 3. In other words, in the example of FIG.15, symbols are sorted in the time axis direction. However, FIG. 15 isan example, and the relationship between symbol number and time is notlimited thereto.

Note that in FIG. 15, each symbol is designated zpq(i), but the symbolsmay also be symbols generated by multiplexing signals directed atmultiple users by the multiplexing signal processor 104 in FIG. 1. Also,the example of FIG. 15 may also be the symbol arrangement in the case inwhich each from the radio section $1 (106_1) to the radio section $N(106_N) in FIG. 1 includes an interleaver (the part that sorts symbols),and each interleaver sorts the symbols. The position where interleavingis executed is not limited to the user signal processor or the radiosection.

FIG. 16 is a diagram illustrating an example of a symbol arrangementwith respect to the frequency axis of the weighted signal 304A (zp1(i))and the phase-changed signal 306B (zp2(i)).

In the example of FIG. 16, the symbol zpq(0) with the symbol number i=0is arranged at carrier 0, the symbol zpq(1) with the symbol number i=1is arranged at carrier 16, the symbol zpq(2) with the symbol number i=2is arranged at carrier 12, and the symbol zpq(3) with the symbol numberi=3 is arranged at carrier 5. In this way, symbols are arranged withrespect to the frequency axis of the weighted signal 304A (zp1(i)) andthe phase-changed signal 306B (zp2(i)) in FIG. 3. However, FIG. 16 is anexample, and the relationship between symbol number and frequency is notlimited thereto.

Note that in FIG. 16, each symbol is designated zpq(i), but the symbolsmay also be symbols generated by multiplexing signals directed atmultiple users by the multiplexing signal processor 104 in FIG. 1. Also,the example of FIG. 16 may also be the symbol arrangement in the case inwhich each from the radio section $1 (106_1) to the radio section $N(106_N) in FIG. 1 includes an interleaver (the part that sorts symbols),and each interleaver sorts the symbols. The position where interleavingis executed is not limited to the user signal processor or the radiosection.

FIG. 17 is a diagram illustrating an example of symbol arrangement withrespect to the time/frequency axes of the weighted signal 304A (zp1(i))and the phase-changed signal 306B (zp2(i)).

In the example of FIG. 17, the symbol zpq(0) with the symbol number i=0is arranged at time 1 and carrier 1, the symbol zpq(1) with the symbolnumber i=1 is arranged at time 3 and carrier 3, the symbol zpq(2) withthe symbol number i=2 is arranged at time 1 and carrier 0, and thesymbol zpq(3) with the symbol number i=3 is arranged at time 1 andcarrier 3. In this way, symbols are arranged with respect to the timeand frequency axes of the weighted signal 304A (zp1(i)) and thephase-changed signal 306B (zp2(i)) in FIG. 3. However, FIG. 17 is anexample, and the relationship between symbol number and time/frequencyis not limited thereto.

Note that in FIG. 17, each symbol is designated zpq(i), but the symbolsmay also be symbols generated by multiplexing signals directed atmultiple users by the multiplexing signal processor 104 in FIG. 1. Also,the example of FIG. 17 may also be the symbol arrangement in the case inwhich each from the radio section $1 (106_1) to the radio section $N(106_N) in FIG. 1 includes an interleaver (the part that sorts symbols),and each interleaver sorts the symbols. The position where interleavingis executed is not limited to the user signal processor or the radiosection.

Note that although symbol arranging is executed in the user #p signalprocessor 102_p by the error-correcting coder 202 and/or the mapper 204illustrated in FIG. 2, for example, the configuration is not limitedthereto. As described earlier, it is also possible to take aconfiguration in which each from the radio section $1 (106_1) to theradio section $N (106_N) in FIG. 1 includes an interleaver (the partthat sorts symbols), and each interleaver sorts the symbols.Alternatively, the multiplexing signal processor 104 may include aninterleaver, and the interleaver may execute the symbol arrangingillustrated in FIGS. 12 to 17. Hereinafter, the multiplexing signalprocessor 104 in the case of including an interleaver will be describedusing FIG. 18.

<Different Example of Configuration of Multiplexing Signal Processor>

FIG. 18 is a diagram illustrating the configuration in the case in whichthe multiplexing signal processor 104 in FIG. 1 includes an interleaver(the part that sorts symbols).

A user #1 interleaver (sorter) 1802_1 accepts signal-processed signals1801_1_1 and 1801_1_2, as well as a control signal 1800 as input. Thesignal-processed signals 1801_1_1 and 1801_1_2 correspond to the user #1first baseband signal 103_1_1 and the user #1 second baseband signal103_1_2 in FIG. 1, respectively. The control signal 1800 corresponds tothe control signal 100 in FIG. 1.

The user #1 interleaver (sorter) 1802_1, following the control signal1800, for example, sorts symbols like in FIGS. 12 to 17, and outputsuser #1 sorted signals 1803_1 and 1803_2.

Note that multiplexing signal processor 104 is similarly provided with auser #2 interleaver to a user #M interleaver. Each from the user #2interleaver to the user #M interleaver includes functions similar to theuser #1 interleaver 1802_1.

A signal processor 1804 accepts the control signal 1800, the user #1sorted signals 1803_1 and 1803_2, and the like as input. Also, thesorted signals of other users are also input into the signal processor1804. Following the control signal 1800, the signal processor 1804executes signal processing such as the weight combining describedearlier on the sorted signals, and outputs multiplexed signal $1baseband signal 1805_1 to multiplexed signal $N baseband signal 1805_N.Note that the multiplexed signal $1 baseband signal 1805_1 to themultiplexed signal $N baseband signal 1805_N correspond to themultiplexed signal $1 baseband signal 105_1 to the multiplexed signal $Nbaseband signal 105_N in FIG. 1, respectively.

The above thus describes an example of a transmission apparatusaccording to the present embodiment. Next, an example of theconfiguration of a reception apparatus according to the presentembodiment will be described.

<Example of Configuration of Reception Apparatus>

FIG. 19 is a diagram illustrating an example of the configuration of thereception apparatus in the present embodiment. The reception apparatusin FIG. 19 is the reception apparatus of terminals corresponding fromuser #1 to user #p from among users #M that receive a modulated signalwhen the transmission apparatus in FIG. 1 transmits a transmissionsignal with the frame configuration in FIGS. 8 and 9 or FIGS. 10 and 11,for example.

A radio section 1903X accepts a received signal 1902X received by anantenna section #X (1901X) as input. The radio section 1903X performsreception processing such as frequency conversion and a Fouriertransform, and outputs a baseband signal 1904X to a modulated signal u1channel estimator 1905_1 and a modulated signal u2 channel estimator1905_2.

Similarly, the radio section 1903Y accepts a received signal 1902Yreceived by an antenna section #Y (1901Y) as input. The radio section1903Y performs reception processing such as frequency conversion and aFourier transform, and outputs a baseband signal 1904Y.

Note that FIG. 19 illustrates a configuration in which a control signal1910 is input into the antenna section #X (1901X) and the antennasection #Y (1901Y), but a configuration in which the control signal 1910is not input is also acceptable. The configuration of the antennasections in which the control signal 1910 is present as input will bedescribed later.

The modulated signal u1 channel estimator 1905_1 and the modulatedsignal u2 channel estimator 1905_2 execute channel estimation on thebasis of the baseband signal 1904X. A modulated signal u1 channelestimator 1907_1 and a modulated signal u2 channel estimator 1907_2execute channel estimation on the basis of the baseband signal 1904X.Channel estimation will be described with reference to FIG. 20.

FIG. 20 is a diagram illustrating the relationship between atransmission apparatus and a reception apparatus. The antenna 2001_1 and2001_2 in FIG. 20 are transmission antennas. The antenna 2001_1 in FIG.20 corresponds to the antenna section in FIG. 1 used to transmit atransmission signal u1(i), for example. Additionally, the antenna 2001_2in FIG. 20 corresponds to the antenna section in FIG. 1 used to transmita transmission signal u2(i), for example. Note that the correspondencebetween FIG. 20 and FIG. 1 is not limited to the above.

Additionally, the antenna 2002_1 and 2002_2 in FIG. 20 are receptionantennas. The antenna 2002_1 in FIG. 20 corresponds to the antennasection #X (1901X) in FIG. 19. The antenna 2002_2 in FIG. 20 correspondsto the antenna section #Y (1901Y) in FIG. 19.

Like in FIG. 20, the signal transmitted from the transmission antenna2001_1 is designated u1(i), the signal transmitted from the transmissionantenna 2001_2 is designated u2(i), the signal received by the receivingantenna 2002_1 is designated r1(i), and the signal received by thereception antenna 2002_2 is designated r2(i). Note that i indicates thesymbol number, and is, for example, an integer equal to 0 or greater.

Additionally, a propagation coefficient from the transmission antenna2001_1 to the reception antenna 2002_1 is designated h11(i), apropagation coefficient from the transmission antenna 2001_1 to thereception antenna 2002_2 is designated h21(i), a propagation coefficientfrom the transmission antenna 2001_2 to the reception antenna 2002_1 isdesignated h12(i), and a propagation coefficient from the transmissionantenna 2001_2 to the reception antenna 2002_2 is designated h22(i).Then, the relation expressed in the following Formula (41) holds.

$\begin{matrix}{\begin{pmatrix}{r\; 1(i)} \\{r2(i)}\end{pmatrix} = {{\begin{pmatrix}{h\; 11(i)} & {h12(i)} \\{h\; 21(i)} & {h22(i)}\end{pmatrix}\begin{pmatrix}{u1(i)} \\{u2(i)}\end{pmatrix}} + \begin{pmatrix}{n\; 1(i)} \\{n2(i)}\end{pmatrix}}} & (41)\end{matrix}$Note that n1(i) and n2(i) are noise.

The modulated signal u1 channel estimator 1905_1 in FIG. 19 accepts thebaseband signal 1904X as input, uses the preamble and/or the pilotsymbol in FIGS. 8 and 9 (or FIGS. 10 and 11) to execute channelestimation of the modulated signal u1, or in other words, estimatesh11(i) of Formula (41), and outputs a channel estimation signal 1906_1.

The modulated signal u2 channel estimator 1905_2 accepts the basebandsignal 1904X as input, uses the preamble and/or the pilot symbol inFIGS. 8 and 9 (or FIGS. 10 and 11) to execute channel estimation of themodulated signal u2, or in other words, estimates h12(i) of Formula(41), and outputs a channel estimation signal 1906_2.

The modulated signal u1 channel estimator 1907_1 accepts the basebandsignal 1904Y as input, uses the preamble and/or the pilot symbol inFIGS. 8 and 9 (or FIGS. 10 and 11) to execute channel estimation of themodulated signal u1, or in other words, estimates h21(i) of Formula(41), and outputs a channel estimation signal 1908_1.

The modulated signal u2 channel estimator 1907_2 accepts the basebandsignal 1904Y as input, uses the preamble and/or the pilot symbol inFIGS. 8 and 9 (or FIGS. 10 and 11) to execute channel estimation of themodulated signal u2, or in other words, estimates h22(i) of Formula(41), and outputs a channel estimation signal 1908_2.

A control information decoder 1909 that accepts the baseband signals1904X and 1904Y as input demodulates and decodes the control informationin FIGS. 8 and 9 (or FIGS. 10 and 11), and outputs a control signal 1910including control information.

A signal processor 1911 accepts the channel estimation signals 1906_1,1906_2, 1908_1, and 1908_2, the baseband signals 1904X and 1904Y, andthe control signal 1910 as input. The signal processor 1911 executesdemodulation and decoding using the relationship in Formula (41) andalso on the basis of the control information in the control signal 1910(for example, information about the modulation scheme, and a schemerelated to the error-correcting code), and outputs received data 1912.

Note that the control signal 1910 does not have to be generated by amethod like that of FIG. 19. For example, the control signal 1910 inFIG. 19 may also be generated on the basis of information transmitted bythe apparatus (FIG. 1) on the other end of the communication in FIG. 19.Alternatively, the reception apparatus in FIG. 19 may be provided withan input section, and the control signal 1910 may also be generated onthe basis of information input from the input section.

<Example of Configuration of Antenna Section>

Next, the configuration of the antenna sections in which the controlsignal 1910 is present as input will be described. FIG. 21 is a diagramillustrating an example of the configuration of the antenna section(antenna section #X (1901X) or antenna section #Y (1901Y)) in FIG. 19.Note that the example in FIG. 19 is an example in which the antennasection is configured with four antennas 2101_1 to 2101_4.

A multiplier 2103_1 accepts a received signal 2102_1 received by theantenna 2101_1 and the control signal 2100 as input. On the basis ofinformation about a multiplication coefficient included in the controlsignal 2100, the multiplier 2103_1 multiplies the received signal 2102_1by the multiplication coefficient, and outputs a multiplied signal2104_1.

Provided that the received signal 2102_1 is Rx1(t) (where t is time),and the multiplication coefficient is D1 (where D1 may be defined as acomplex number, and thus may also be a real number), the multipliedsignal 2104_1 is expressed as Rx1(t)×D1.

A multiplier 2103_2 accepts a received signal 2102_2 received by theantenna 2101_2 and the control signal 2100 as input. On the basis ofinformation about a multiplication coefficient included in the controlsignal 2100, the multiplier 2103_2 multiplies the received signal 2102_2by the multiplication coefficient, and outputs a multiplied signal2104_2.

Provided that the received signal 2102_2 is Rx2(t), and themultiplication coefficient is D2 (where D2 may be defined as a complexnumber, and thus may also be a real number), the multiplied signal2104_2 is expressed as Rx2(t)×D2.

A multiplier 2103_3 accepts a received signal 2102_3 received by theantenna 2101_3 and the control signal 2100 as input. On the basis ofinformation about a multiplication coefficient included in the controlsignal 2100, the multiplier 2103_3 multiplies the received signal 2102_3by the multiplication coefficient, and outputs a multiplied signal2104_3.

Provided that the received signal 2102_3 is Rx3(t), and themultiplication coefficient is D3 (where D3 may be defined as a complexnumber, and thus may also be a real number), the multiplied signal2104_3 is expressed as Rx3(t)×D3.

A multiplier 2103_4 accepts a received signal 2102_4 received by theantenna 2101_4 and the control signal 2100 as input. On the basis ofinformation about a multiplication coefficient included in the controlsignal 2100, the multiplier 2103_4 multiplies the received signal 2102_4by the multiplication coefficient, and outputs a multiplied signal2104_4.

Provided that the received signal 2102_4 is Rx4(t), and themultiplication coefficient is D4 (where D4 may be defined as a complexnumber, and thus may also be a real number), the multiplied signal2104_4 is expressed as Rx4(t)×D4.

A combiner 2105 accepts the multiplied signals 2104_1, 2104_2, 2104_3,and 2104_4 as input. The combiner 2105 combines the multiplied signals2104_1, 2104_2, 2104_3, and 2104_4, and outputs a combined signal 2106.Note that the combined signal 2106 is expressed asRx1(t)×D1+Rx2(t)×D2+Rx3(t)×D3+Rx4(t)×D4.

In FIG. 21, an example is described in which the antenna section isconfigured with four antennas (and four multipliers), but the number ofantennas is not limited to four, and it is sufficient for the antennasection to include two or more antennas.

Additionally, in the case in which the antenna section #X (1901X) inFIG. 19 takes the configuration of FIG. 21, the received signal 1902Xcorresponds to the combined signal 2106 in FIG. 21, and the controlsignal 1910 corresponds to the control signal 2100 in FIG. 21. Also, inthe case in which the antenna section #Y (1901Y) in FIG. 19 takes theconfiguration of FIG. 21, the received signal 1902Y corresponds to thecombined signal 2106 in FIG. 21, and the control signal 1910 correspondsto the control signal 2100 in FIG. 21.

However, the antenna section #X (1901X) and the antenna section #Y(1901Y) do not have to be configured like FIG. 21, and as describedearlier, the antenna sections do not have to accept the control signal1910 as input. The antenna section #X (1901X) and the antenna section #Y(1901Y) may also have one antenna each.

Note that the control signal 1910 may also be generated on the basis ofinformation transmitted by the transmission apparatus on the other endof the communication. Alternatively, an input section may be provided,and the control signal 1910 may also be generated on the basis ofinformation input from the input section.

As above, in the present embodiment, by having the transmissionapparatus in FIG. 1 use multiple antennas to transmit the modulatedsignals (baseband signals) of multiple users at identical times andidentical frequencies (bands), the advantageous effect of improved datatransmission efficiency of the transmission apparatus in FIG. 1 may beobtained. Note that the transmission apparatus in FIG. 1 sets whether totransmit multiple streams or transmit a single stream (or not totransmit a modulated signal) for each user, and in addition, sets amodulation scheme (in the case of multiple mappers, a set of modulationschemes) and an error-correcting coding scheme for each user, andthereby is able to control the data transmission efficiency favorably.

Note that when the transmission apparatus in FIG. 1 transmits multiplemodulated signals (baseband signals) to users, by performing phasechange, in an environment in which direct waves are dominant, anadvantageous effect of raising the possibility of being able to avoidfalling into a steady reception state, and improving the received signalquality of data at a reception apparatus on the other end ofcommunication may be obtained.

Embodiment 2

In the present embodiment, a communication apparatus including thetransmission apparatus of FIG. 1 described in Embodiment 1, acommunication apparatus provided with the reception apparatus of FIG. 19described in Embodiment 1, and an example of the flow of communicationbetween the communication apparatus will be described.

Note for the sake of the following description, the communicationapparatus provided with the transmission apparatus of FIG. 1 will becalled the “base station (access point (AP))”, and the communicationapparatus provided with the reception apparatus of FIG. 19 will becalled the “terminal”.

Consequently, the user #1 signal processor 102_1 is a signal processorfor generating a modulated signal for transmitting data to terminal #1,the user #2 signal processor 102_2 is a signal processor for generatinga modulated signal for transmitting data to terminal #2, and the user #Msignal processor 102_M is a signal processor for generating a modulatedsignal for transmitting data to terminal #M.

FIG. 22 is a diagram illustrating an example of a configuration providedtogether with the transmission apparatus of FIG. 1 in the base station(AP). In FIG. 22, parts of the configuration which are similar to FIG. 1are denoted with the same numbers, and description is omitted.

A radio section group 153 accepts a received signal group 152 receivedby a reception antenna group 151 as input. The radio section group 153performs processing such as frequency conversion on the received signalgroup 152, and outputs a baseband signal group 154 to a signal processor155.

The signal processor 155 executes processing such as demodulation anderror-correcting decoding on the input baseband signal group, andoutputs received data 156 as well as control information 157. At thistime, the control information 157 includes feedback informationtransmitted by each terminal.

A setting section 158 accepts base station (AP) settings information 159and the control information 157 as input. The setting section 158“decides the error-correcting coding method, the transmission method,the modulation scheme (or modulation scheme set), and the like in theuser #1 signal processor 102_1 of FIG. 1”, “decides the error-correctingcoding method, the transmission method, the modulation scheme (ormodulation scheme set), and the like in the user #2 signal processor102_2 of FIG. 1”, and “decides the error-correcting coding method, thetransmission method, the modulation scheme (or modulation scheme set),and the like in the user #M signal processor 102_M of FIG. 1”, andoutputs a signal including the decided information as the control signal100.

Also, on the basis of the feedback information transmitted by eachterminal and included in the control information 157, the settingsection 158 decides the processing method to be executed by themultiplexing signal processor 104, and outputs a signal includinginformation about the decided processing method as the control signal100.

Note that in FIG. 22, the term “group” is used, but it is sufficient tohave at least one reception subsystem.

FIG. 23 is a diagram illustrating an example of a configuration providedtogether with the reception apparatus of FIG. 19 in a terminal. In FIG.23, parts which operate similarly to FIG. 19 are denoted with the samenumbers.

The signal processor 1911 accepts the channel estimation signal 1906_1,the channel estimation signal 1906_2, the baseband signal 1904X, thechannel estimation signal 1908_1, the channel estimation signal 1908_2,the baseband signal 1904Y, and the control signal 1910 as input. Thesignal processor 1911 executes demodulation and error-correctingdecoding processing, and outputs the received data 1912. Also, thesignal processor 1911, on the basis of a signal transmitted by the basestation (AP), generates feedback information related to the state of thereceived signal, and outputs feedback information 1999.

A transmission signal processor 1952 accepts data 1951 and the feedbackinformation 1999 as input. The transmission signal processor 1952performs processing such as error-correcting coding and modulation onthe data 1951 and the feedback information 1999, generates a basebandsignal group 1953, and outputs the baseband signal group 1953 to a radiosection group 1954.

The radio section group 1954 performs processing such as frequencyconversion and amplification on the input baseband signal group 1953,and generates a transmission signal group 1955. The radio section group1954 outputs the transmission signal group 1955 to a transmissionantenna group 1956. Subsequently, the transmission signal group 1955 isoutput as radio waves from the transmission antenna group 1956.

Note that in FIG. 23, the term “group” is used, but it is sufficient tohave at least one transmission subsystem.

The base station (AP) transmits a signal to a terminal with theconfiguration of the transmission apparatus in FIG. 1, and receives asignal from the terminal with the configuration in FIG. 22. The terminalreceives a signal from the base station (AP) with the configuration ofthe reception apparatus in FIG. 19, and transmits a signal to the basestation with the configuration in FIG. 23. With these configurations,communication between the base station (AP) and the terminal isexecuted.

Next, the flow of communication between the base station (AP) andterminals will be described.

FIG. 24 is a diagram illustrating an example of the relationship betweena base station (AP) and terminals. The base station (AP) 2400 uses theuser #1 signal processor 102_1 in FIG. 1 to generate a modulated signalto transmit to terminal #1 (2401_1), for example; uses user #2 signalprocessor 102_2 in FIG. 1 to generate a modulated signal to transmit toterminal #2 (2401_2), for example, and uses the user #M signal processor102_M to generate a modulated signal to transmit to terminal #M(2401_M), for example.

The base station (AP) 2400 generates a transmission directivity 2411_1,and in addition, terminal #1 (2401_1) generates a reception directivity2421_1. Additionally, by the transmission directivity 2411_1 and thereception directivity 2421_1, the transmission signal for terminal #1transmitted by the base station (AP) 2400 is received by terminal #1(2401_1).

Also, the base station (AP) 2400 generates a transmission directivity2411_2, and in addition, terminal #2 (2401_2) generates a receptiondirectivity 2421_2. Additionally, by the transmission directivity 2411_2and the reception directivity 2421_2, the transmission signal forterminal #2 transmitted by the base station (AP) 2400 is received byterminal #2 (2401_2).

The base station (AP) 2400 generates a transmission directivity 2411_M,and in addition, terminal #M (2401_M) generates a reception directivity2421_M. Additionally, by the transmission directivity 2411_M and thereception directivity 2421_M, the transmission signal for terminal #Mtransmitted by the base station (AP) 2400 is received by terminal #M(2401_M).

The example of FIG. 24 assumes that the base station (AP) 2400 istransmitting the modulated signal to transmit to terminal #1, themodulated signal to transmit to terminal #2, and the modulated signal totransmit to terminal #M at identical times and identical frequencies(bands). This point has been described in Embodiment 1. Note thatalthough FIG. 24 illustrates “transmitting the modulated signal totransmit to terminal #1, the modulated signal to transmit to terminal#2, and the modulated signal to transmit to terminal #M at identicaltimes and identical frequencies (bands)”, this is merely one example.The number of modulated signals that the base station (AP) 2400transmits at identical times and identical frequencies (bands) is notlimited to this example. Also, times at which modulated signals do notoverlap may also exist.

FIG. 25 is a diagram illustrating an example of the temporal flow ofcommunication between the base station (AP) and terminals. In FIG. 25,transmission signals of the base station (AP), transmission signals ofterminal #1, transmission signals of terminal #2, and transmissionsignals of terminal #M are illustrated. Also, the horizontal axis inFIG. 25 represents time. Note that terminals other than terminal #1,terminal #2, and terminal #M may also transmit transmission signals.

As illustrated in FIG. 25, suppose that terminal #1 issues an accessrequest (transmission of data by the base station (AP)) 2501_1 to thebase station (AP). Similarly, suppose that terminal #2 issues an accessrequest (transmission of data by the base station (AP)) 2501_2 to thebase station (AP). Suppose that terminal #M issues an access request(transmission of data by the base station (AP)) 2501_M to the basestation (AP).

In response, suppose that the base station (AP) transmits referencesymbols (2502). For example, as the reference symbols 2502, assume thatPSK symbols which are known to the terminals are transmitted. However,the configuration of the reference symbols 2502 is not limited thereto.Note that the reference symbols 2502 correspond to the (common)reference signal 199 illustrated in FIG. 1.

Meanwhile, terminal #1 receives the reference symbols 2502 transmittedby the base station. Additionally, for example, terminal #1 estimatesthe received signal state at each reception antenna of terminal #1, andtransmits information about the received signal state at each receptionantenna as feedback information 2503_1. Similarly, terminal #2 receivesthe reference symbols 2502 transmitted by the base station.Additionally, for example, terminal #2 estimates the received signalstate at each reception antenna of terminal #2, and transmitsinformation about the received signal state at each reception antenna asfeedback information 2503_2. Similarly, terminal #M receives thereference symbols 2502 transmitted by the base station. For example,terminal #M estimates the received signal state at each receptionantenna of terminal #M, and transmits information about the receivedsignal state at each reception antenna as feedback information 2503_M.

The base station (AP) receives the feedback information transmitted byeach terminal. For example, in FIG. 22, suppose that the controlinformation 157 includes the feedback information transmitted by eachterminal. The setting section 158 in FIG. 22 accepts the controlinformation 157 including the feedback information transmitted by eachterminal as input, decides the processing method to be executed by themultiplexing signal processor 104 in FIG. 1, and outputs the controlsignal 100 including this information.

Additionally, as illustrated in FIG. 24, for example, the base station(AP) transmits each data symbol to each terminal (2504). Note that for“transmit each data symbol and the like” 2504 illustrated in FIG. 25,symbols other than data symbols, such as pilot symbols, controlinformation symbols, reference symbols, and a preamble may also bepresent. The base station (AP) transmits the modulated signals of eachterminal using identical times and identical frequencies (bands). Notethat this point has been described in detail in Embodiment 1.

Embodiment 3

In Embodiment 1, an example is described in which primarily, when thetransmission apparatus in FIG. 1 transmits multiple modulated signals touser #p, to generate the multiple modulated signals, the phase of atleast one of the modulated signals after precoding is changed in thephase changer 305B (see FIGS. 3 and 4). Embodiment 3 describes a processin which the transmission apparatus in FIG. 1 switches between“executing phase change, not executing phase change” in the phasechanger 305B with the control signal 300. Also, Embodiment 3 describes aprocess of changing the transmission scheme of the signal on the basisof information received from the other end of the communication when thetransmission apparatus in FIG. 1 transmits a signal.

Note that the following describes a case in which the base station (AP)provided with the transmission apparatus in FIG. 1 communicates withterminals.

At this time, suppose that the base station (AP) is able to transmitmultiple modulated signals including multiple streams of data to eachuser (each terminal) using multiple antennas.

For example, suppose that the base station (AP) is provided with thetransmission apparatus in FIG. 1 to transmit multiple modulated signalsincluding multiple streams of data to user #p (where p is an integerfrom 1 to M) using multiple antennas.

In FIG. 1, when transmitting the multiple modulated signals to user #p,to generate the multiple modulated signals, the phase of at least one ofthe modulated signals after precoding is changed. Note that since theoperation when executing the phase change has been described inEmbodiment 1, a description is omitted here.

At this point, for the base station (AP) to generate multiple modulatedsignals including multiple streams of data for user #p, suppose that thebase station (AP) is able to switch between “executing phase change, notexecuting phase change” with a control signal. In other words, supposethat in the phase changer 305B of FIG. 3, it is possible to switchbetween “executing phase change, not executing phase change” with thecontrol signal 300. Note that the operation when executing the phasechange has been described in Embodiment 1. Additionally, in the case ofnot executing phase change, the phase changer 305B outputs the signal304B as 306B.

Consequently, operations like the following are executed in the case ofexecuting phase change and the case of not executing phase change.

<Case of Executing Phase Change>

The base station (AP) executes phase change on at least one modulatedsignal. Subsequently, the multiple modulated signals are transmittedusing multiple antennas.

Note that the transmission method by which phase change is executed onat least one modulated signal and the multiple modulated signals aretransmitted using multiple antennas is as described in Embodiment 1, forexample.

<Case of not Executing Phase Change>

The base station (AP) executes precoding (weight combining) on themodulated signals (baseband signals) of multiple streams, and transmitsthe generated multiple modulated signals using multiple antennas.However, the precoder (weight combiner) does not have to executeprecoding.

Note that, for example, the base station (AP) transmits controlinformation for notifying the terminal on the other end of thecommunication of the setting for executing or not executing phase changeusing the preamble.

As described above, “phase change is executed on at least one modulatedsignal”. Specifically, FIG. 3 is used to describe executing phase changeon one modulated signal among multiple modulated signals. Herein,instead of FIG. 3, FIG. 26 will be used to describe the case of“executing phase change on multiple modulated signals”.

FIG. 26 is a diagram illustrating a different example from FIG. 3 of theconfiguration of the signal processor 206 in FIG. 2. In FIG. 26, thepoints which are different from FIG. 3 will be described.

A phase changer 305A accepts the control signal 300 as input. On thebasis of the control signal 300, the phase changer 305A determineswhether or not to execute phase change. In the case of determining toexecute phase change, the phase changer 305A executes phase change onthe user #p weighted signal 304A (zp1′(t)), and outputs a phase-changedsignal 306A. In the case of determining not to execute phase change, thephase changer 305A outputs a signal 306A without performing phase changeon the user #p weighted signal 304A (zp1′(t)).

In FIG. 26, zp1(i) and zp2(i) are based on Formula (3), similarly toEmbodiment 1. Additionally, the case in which phase change is executedon zp1(i) and zp2(i) in FIG. 26 may be expressed by the followingFormula (42).

$\begin{matrix}\begin{matrix}{\begin{pmatrix}{zp1(i)} \\{zp2(i)}\end{pmatrix} = {\begin{pmatrix}{{Yp}(i)} & 0 \\0 & {{yp}(i)}\end{pmatrix}\begin{pmatrix}a & b \\c & d\end{pmatrix}\begin{pmatrix}{sp1(i)} \\{{sp2}(i)}\end{pmatrix}}} \\{= {\begin{pmatrix}e^{j \times {{\lambda p}{(i)}}} & 0 \\0 & e^{j \times {{\delta p}{(i)}}}\end{pmatrix}\begin{pmatrix}a & b \\c & d\end{pmatrix}\begin{pmatrix}{{sp}\; 1(i)} \\{{sp2}(i)}\end{pmatrix}}}\end{matrix} & (42)\end{matrix}$At this time, λp(i) is a real number. Additionally, zp1(i) and zp2(i)are transmitted from the transmission apparatus at identical times andidentical frequencies (identical frequency bands). Additionally, for thephase change in the phase changer 305A, for example, a method thatchanges the phase periodically or regularly is conceivable.

Note that in other embodiments such as Embodiment 1 and Embodiment 2,FIG. 26 may be used instead of FIG. 3 as the configuration of the signalprocessor 206 in FIG. 2, and each embodiment is capable of carrying outthe above.

Next, communication between the base station (AP) and terminal #p aswell as a process based on data transmitted and received during suchcommunication will be described.

FIG. 27 is a diagram illustrating an example of communication betweenthe base station (AP) and terminal #p. FIG. 27 illustrates the state ofthe base station (AP) at the time of a transmission signal, and thestate of terminal #p at the time of the transmission signal. Note thatin FIG. 27, the horizontal axis is time.

First, the base station (AP) transmits a transmission request 2701indicating “request information for transmitting a modulated signal” toterminal #p.

Subsequently, terminal #p receives the transmission request 2701transmitted by the base station (AP), and transmits reception capabilitynotification symbols 2702, which indicate what the terminal is able toreceive, to the base station (AP).

The base station (AP) receives the reception capability notificationsymbols 2702 transmitted by terminal #p, and on the basis of theinformation of the reception capability notification symbols 2702,decides the error-correcting coding method, the modulation scheme (orset of modulation schemes), and the transmission method. On the basis ofthese decided methods, the base station (AP) performs error-correctingcode, mapping in the modulation scheme, and other signal processing(such as precoding and phase change, for example) on the information(data) to be transmitted, and transmits a modulated signal 2703including data symbols and the like to terminal #p.

Note that the data symbols and the like 2703 may also include controlinformation symbols, for example. At this time, when transmitting datasymbols using “a transmission method for transmitting multiple modulatedsignals including multiple streams of data using multiple antennas”, itis preferable to transmit a control symbol including information fornotifying the other end of the communication whether phase change hasbeen executed on at least one modulated signal, or the above phasechange has not been executed. With this arrangement, the other end ofthe communication is able to change the demodulation method easily.

Terminal #p receives the data symbols and the like 2703 transmitted bythe base station, and obtains data.

Note that the exchange between the base station (AP) and the terminal inFIG. 27 is executed by one or more terminals from among terminal #1 toterminal #M, and the base station (AP). Additionally the data symbols(including other symbols) transmitted to each terminal are transmittedusing identical times and identical frequencies (bands) by the basestation. This point has been described in Embodiment 1, Embodiment 2,and the like.

FIG. 28 is a diagram illustrating an example of data included in thereception capability notification symbols 2702 transmitted by terminal#p in FIG. 27. The data included in the reception capabilitynotification symbols 2702 is data indicating the reception capability interminal #p, for example. By having terminal #p transmit data indicatingthe reception capability to the base station (AP), the base station (AP)is able to transmit a transmission signal to terminal #p in accordancewith the reception capability.

In FIG. 28, 2801 is data related to “demodulation of modulated signalwith phase change supported/unsupported”, and 2802 is data related to“reception directivity control supported/unsupported”.

In the data 2801 related to “demodulation of modulated signal with phasechange supported/unsupported”, “demodulation of modulated signal withphase change supported” refers to the following.

“demodulation of modulated signal with phase change supported”:

-   -   This means that, in the case in which the base station (AP)        executes phase change on at least one modulated signal and        transmits multiple modulated signals (multiple modulated signals        including multiple streams) using multiple antennas, terminal #p        is able to receive and demodulate the modulated signals. In        other words, this means that terminal #p is able to execute        demodulation that takes the phase change into account, and is        able to obtain data. Note that the transmission method by which        phase change is executed on at least one modulated signal and        the multiple modulated signals are transmitted using multiple        antennas has been described already in an embodiment.

In the data 2801 related to “demodulation of modulated signal with phasechange supported/unsupported”, “demodulation of modulated signal withphase change unsupported” refers to the following.

“demodulation of modulated signal with phase change unsupported”:

-   -   This means that, when the base station (AP) executes phase        change on at least one modulated signal and transmits multiple        modulated signals (multiple modulated signals including multiple        streams) using multiple antennas, terminal #p is unable to        demodulate even if the modulated signals are received. In other        words, this means that terminal #p is unable to execute        demodulation that takes the phase change into account. Note that        the transmission method by which phase change is executed on at        least one modulated signal and the multiple modulated signals        are transmitted using multiple antennas has been described        already in an embodiment.

For example, suppose that the data 2801 related to “demodulation ofmodulated signal with phase change supported/unsupported” (hereinaftercalled the data 2801) is expressed by 1-bit data. Additionally, supposethat in the case in which terminal #p “supports phase change” asdescribed above, terminal #p transmits with the data 2801 set to “0”.Also, suppose that in the case in which terminal #p “does not supportphase change” as described above, terminal #p transmits with the data2801 set to “1”. Subsequently, the base station (AP) receives the data2801 transmitted by terminal #p.

In the case in which the data 2801 indicates “phase change supported”(that is, the data 2801 is “0”), and the base station (AP) decides totransmit modulated signals of multiple streams to terminal #p usingmultiple antennas (for example, in the case of deciding to generatemultiple modulated signals for transmitting multiple streams in user #psignal processor 102_p illustrated in FIG. 1), the base station (AP) maygenerate and transmit modulated signals addressed to user #p by eitherof <Method #1> and <Method #2> described below. Alternatively, the basestation (AP) generates and transmits modulated signals addressed to user#p by <Method #2> described below.

<Method #1>

The base station (AP) executes precoding (weight combining) on themodulated signals (baseband signals) of multiple streams to transmit toterminal #p, and transmits the generated multiple modulated signalsusing multiple antennas. At this time, assume that phase change is notperformed. However, as described already, the precoder (weight combiner)does not have to execute precoding.

<Method #2>

The base station (AP) executes phase change on at least one modulatedsignal among the multiple modulated signals to transmit to terminal #p.Subsequently, the base station (AP) transmits the multiple modulatedsignal to terminal #p using multiple antennas.

The important point here is that <Method #2> is included as atransmission method selectable by the base station (AP). Consequently,the base station (AP) may also transmit the modulated signals by amethod other than <Method #1> or <Method #2>.

On the other hand, in the case in which the data 2801 indicates “phasechange unsupported” (that is, the data 2801 is “1”), and the basestation (AP) decides to transmit the modulated signals of multiplestreams to terminal #p using multiple antennas, for example, the basestation (AP) transmits the modulated signals to terminal #p by <Method#1>.

The important point here is that, when transmitting modulated signals toterminal #p, <Method #2> is not included as a selectable transmissionmethod. Consequently, the base station (AP) may also transmit themodulated signals to terminal #p by a transmission method which isdifferent from <Method #1>, but not <Method #2>.

Note that the reception capability notification symbols 2702 may alsoinclude information other than the data 2801. For example, data 2802related to “reception directivity control supported/unsupported”indicating whether or not the reception apparatus of the terminalsupports reception directivity control (hereinafter called the data2802) may be included. Consequently, the configuration of the receptioncapability notification symbols 2702 is not limited to FIG. 28.

For example, in the case in which terminal #p is able to executereception directivity control, the data 2802 is set to “0”. Also, in thecase in which terminal #p is unable to execute reception directivitycontrol, the data 2802 is set to “1”.

Terminal #p transmits reception capability notification symbols 2702including the data 2802, and on the basis of the reception capabilitynotification symbols 2702, the base station (AP) determines whether ornot terminal #p is capable of executing reception directivity control.In the case in which the base station (AP) determines that terminal #p“supports reception directivity control”, the base station (AP) andterminal #p may also transmit training symbols, reference symbols,control information symbols, and the like for the reception directivitycontrol of terminal #p.

FIG. 29 is a diagram illustrating a different example from FIG. 28 ofdata included in the reception capability notification symbols 2702transmitted by terminal #p in FIG. 27. Note that the data 2801 issimilar to FIG. 28.

Next, data 2901 related to “reception for multiple streamssupported/unsupported” in FIG. 29 will be described below.

In the data 2901 related to “reception for multiple streamssupported/unsupported”, “reception for multiple streams supported”refers to the following.

“Reception for multiple streams supported”:

-   -   This means that when the base station (AP) transmits multiple        modulated signals addressed to terminal #p from multiple        antennas to transmit multiple streams to terminal #p, terminal        #p is able to receive and demodulate the multiple modulated        signals addressed to terminal #p transmitted by the base        station.

However, for example, when the base station (AP) transmits multiplemodulated signals addressed to terminal #p from multiple antennas,assume that there is no distinguishing between whether phase change isperformed/not performed. In other words, in the case in which multipletransmission methods are defined as a transmission method by which thebase station (AP) transmits multiple modulated signals addressed toterminal #p by multiple antennas to transmit multiple streams toterminal #p, it is sufficient for there to be at least one transmissionmethod that terminal #p is capable of decoding.

In the data 2901 related to “reception for multiple streamssupported/unsupported”, “reception for multiple streams unsupported”refers to the following.

“Reception for multiple streams unsupported”:

-   -   In the case in which multiple transmission methods are defined        as a transmission method by which the base station transmits        multiple modulated signals addressed to terminal #p by multiple        antennas to transmit multiple streams to terminal #p, the        terminal is unable to demodulate no matter which transmission        method the base station uses to transmit the modulated signals.

For example, suppose that the data 2901 related to “reception formultiple streams supported/unsupported” (hereinafter called the data2901) is expressed by 1-bit data. In the case in which terminal #p“supports reception for multiple streams”, terminal #p sets “0” as thedata 2901. Also, in the case in which terminal #p “does not supportreception for multiple streams”, terminal #p sets “1” as the data 2901.

Note that since the base station (AP) executes phase change on at leastone modulated signal among the multiple modulated signals (the multiplemodulated signals including multiple streams), in the case in whichterminal #p does not support reception for multiple streams, the basestation (AP) is unable to transmit multiple modulated signals, and as aresult, is also unable to execute phase change.

Consequently, in the case in which terminal #p has set “0” as the data2901, the data 2801 is valid. At this time, the base station (AP)decides the transmission method by which to transmit data according tothe data 2801 and the data 2901.

In the case in which terminal #p has set “1” as the data 2901, the data2801 is invalid. At this time, the base station (AP) decides thetransmission method by which to transmit data according to the data2901.

As above, by having the terminal transmit the reception capabilitynotification symbols 2702, and having the base station (AP) decide thetransmission method by which to transmit data on the basis of thesymbols, it is possible to reduce cases in which data is transmitted bya transmission method that terminal #p is unable to demodulate, and thusthere is an advantage of being able to transmit data appropriately toterminal #p. With this arrangement, an advantageous effect of improveddata transmission efficiency of the base station (AP) may be obtained.

In addition, the data 2801 related to “demodulation of modulated signalwith phase change supported/unsupported” exists as the receptioncapability notification symbols 2702. For this reason, in the case inwhich terminal #p supporting demodulation of modulated signal with phasechange communicates with the base station (AP), the base station (AP) isable to appropriately select a mode that “transmits modulated signals bya transmission method that performs phase change”, and thus anadvantageous effect may be obtained whereby terminal #p obtains data ofhigh received signal quality, even in an environment in which directwaves are dominant. Also, in the case in which terminal #p notsupporting demodulation of modulated signal with phase changecommunicates with the base station (AP), the base station (AP) is ableto appropriately select a transmission method that the terminal iscapable of receiving, and thus an advantageous effect of improving thedata transmission efficiency may be obtained.

Note that although the transmission signal of the base station (AP) andthe transmission signal of terminal #p are illustrated in FIG. 27, thetransmission signals are not limited thereto. For example, the signalillustrated as the transmission signal of the base station (AP) in FIG.27 may also be the transmission signal of the terminal, and the signalillustrated as the transmission signal of terminal #p in FIG. 27 mayalso be the transmission signal of the base station (AP).

Alternatively, the signal illustrated as the transmission signal of thebase station (AP) may also be the transmission signal of a terminalother than terminal #p. In other words, the transmission and receptionof the signals illustrated in FIG. 27 may also be transmission andreception between terminals.

Alternatively, the transmission and reception of the signals illustratedin FIG. 27 may also be transmission and reception between base stations(APs).

Note that the configuration is not limited to these examples, andcommunication between communication apparatus is sufficient.

In addition, the data symbols in the data symbols and the like 2703 inFIG. 27 may be signals of a multi-carrier scheme such as OFDM, orsignals of a single-carrier scheme. Similarly, the reception capabilitynotification symbols 2702 in FIG. 27 may be signals of a multi-carrierscheme such as OFDM, or signals of a single-carrier scheme.

For example, when the reception capability notification symbols 2702 inFIG. 27 are treated as a single-carrier scheme, in the case of FIG. 27,the terminal is able to obtain an advantageous effect of reducing powerconsumption.

Note that in the above description, when the base station (AP) iscommunicating with multiple terminals, the base station (AP) receivesreception capability notification symbols (see 2702) from multipleterminals. At this time, each terminal transmits the data illustrated inFIG. 28 or 29 as the “reception capability notification symbols”, forexample, and the base station (AP) decides the transmission method forthe modulated signals addressed to each terminal. Subsequently, whentransmitting modulated signals to multiple terminals, for example, thebase station (AP) transmits the modulated signals addressed to eachterminal by the method described in Embodiment 1 or Embodiment 2.

Next, a different example of the reception capability notificationsymbols 2702 will be described using FIG. 30.

FIG. 30 is a diagram illustrating a different example from FIGS. 28 and29 of data included in the reception capability notification symbols2702 transmitted by terminal #p in FIG. 27. Note that the data 2801related to “demodulation of modulated signal with phase changesupported/unsupported” is similar to FIGS. 28 and 29. Also, the data2901 related to “reception for multiple streams supported/unsupported”is similar to FIG. 29.

Data 3001 related to “supported schemes” in FIG. 30 (hereinafter calledthe data 3001) will be described. The transmission of modulated signalsto the terminals by the base station (AP) and the transmission ofmodulated signals to the base station (AP) by the terminals in FIG. 24are assumed to be the transmission of modulated signals in acommunication scheme in a certain specific frequency (band).Additionally, suppose that, for example, communication scheme #A andcommunication scheme #B exist as the “communication scheme in a certainspecific frequency (band)”.

Note that “communication scheme #A” is assumed not to support a “methodthat transmits multiple modulated signals including multiple streamsusing multiple antennas”. In other words, “communication scheme #A”lacks a selection option for a “method that transmits multiple modulatedsignals including multiple streams using multiple antennas”. Also,“communication scheme #B” is assumed to support a “method that transmitsmultiple modulated signals including multiple streams using multipleantennas”. In other words, as “communication scheme #B”, it is possibleto select a “method that transmits multiple modulated signals includingmultiple streams using multiple antennas”.

For example, assume that the data 3001 is made up of 2 bits.Additionally, assume that the 2-bit data is set as follows.

-   -   In the case in which terminal #p supports “communication scheme        #A” only, the data 3001 is set to “01”. In the case of setting        the data 3001 to “01”, even if the base station (AP) transmits a        modulated signal of “communication scheme #B”, terminal #p is        unable to demodulate and obtain data.    -   In the case in which terminal #p supports “communication scheme        #B” only, the data 3001 is set to “10”. In the case of setting        the data 3001 to “10”, even if the base station (AP) transmits a        modulated signal of “communication scheme #A”, terminal #p is        unable to demodulate and obtain data.    -   In the case in which terminal #p supports both “communication        scheme #A” and “communication scheme #B”, the data 3001 is set        to “11”.

Next, data 3002 related to “multi-carrier scheme supported/unsupported”in FIG. 30 (hereinafter called the data 3002) will be described. Supposethat in “communication scheme #A”, a “single-carrier scheme” and a“multi-carrier scheme such as OFDM” are selectable as the modulatedsignal transmission method. Also, suppose that in “communication scheme#B”, a “single-carrier scheme” and a “multi-carrier scheme such as OFDM”are selectable as the modulated signal transmission method.

For example, assume that the data 3002 is made up of 2 bits.Additionally, assume that the 2-bit data is set as follows.

-   -   In the case in which terminal #p supports the “single-carrier        scheme” only, the data 3002 is set to “01”. In the case of        setting the data 3002 to “01”, even if the base station (AP)        transmits a modulated signal by the “multi-carrier scheme such        as OFDM”, terminal #p is unable to demodulate and obtain data.    -   In the case in which terminal #p supports the “multi-carrier        scheme such as OFDM” only, the data 3002 is set to “10”. In the        case of setting the data 3002 to “10”, even if the base station        (AP) transmits a modulated signal by the “single-carrier        scheme”, terminal #p is unable to demodulate and obtain data.    -   In the case in which terminal #p supports both the        “single-carrier scheme” and the “multi-carrier scheme such as        OFDM”, the data 3002 is set to “11”.

Next, data 3003 related to “supported error-correcting coding schemes”in FIG. 30 (hereinafter called the data 3003) will be described. Forexample, suppose that “error-correcting coding scheme #C” is an“error-correcting coding scheme supporting one or more code rates with acode length (block length) of c bits (where c is an integer equal to 1or greater)”. Suppose that “error-correcting coding scheme #D” is an“error-correcting coding scheme supporting one or more code rates with acode length (block length) of d bits (where d is an integer equal to 1or greater, and the relationship of d being greater than c (d>c)holds)”. Note that as the method supporting one or more code rates,different error-correcting codes may be used for each code rate, or oneor more code rates may be supported by puncturing. Also, one or morecode rates may be supported by both of the above.

Note that in “communication scheme #A”, it is assumed that only“error-correcting coding scheme #C” is selectable, while in“communication scheme #B”, it is assumed that “error-correcting codingscheme #C” and “error-correcting coding scheme #D” are selectable.

For example, assume that the data 3003 is made up of 2 bits.Additionally, assume that the 2-bit data is set as follows.

-   -   In the case in which terminal #p supports “error-correcting        coding scheme #C” only, the data 3003 is set to “01”. In the        case of setting the data 3003 to “01”, even if the base station        (AP) uses “error-correcting coding scheme #D” to generate and        transmit a modulated signal, terminal #p is unable to        demodulate/decode and obtain data.    -   In the case in which terminal #p supports “error-correcting        coding scheme #D” only, the data 3003 is set to “10”. In the        case of setting the data 3003 to “10”, even if the base station        (AP) uses “error-correcting coding scheme #C” to generate and        transmit a modulated signal, terminal #p is unable to        demodulate/decode and obtain data.    -   In the case in which terminal #p supports both “error-correcting        coding scheme #C” and “error-correcting coding scheme #D”, the        data 3003 is set to “11”.

The base station (AP) receives the reception capability notificationsymbols 2702 transmitted by terminal #p and configured like in FIG. 30,for example. Additionally, on the basis of the content of the receptioncapability notification symbols 2702, the base station (AP) decides themethod of generating modulated signals including data symbols addressedto terminal #p, and transmits the modulated signals addressed toterminal #p.

At this time, the characteristic points will be described.

Example 1

In the case in which terminal #p transmits with the data 3001 set to“01” (that is, supporting “communication scheme #A”), the base station(AP) obtaining this data determines that in “communication scheme #A”,since the “error-correcting coding scheme #D” cannot be selected, thedata 3003 is invalid. Subsequently, when generating the modulatedsignals addressed to terminal #p, the base station (AP) uses the“error-correcting coding scheme #C” to execute error-correcting coding.

Example 2

In the case in which terminal #p transmits with the data 3001 set to“01” (that is, supporting “communication scheme #A”), the base station(AP) obtaining this data determines that in “communication scheme #A”,since the “method that transmits multiple modulated signals includingmultiple streams using multiple antennas” is not supported, the data2801 and the data 2901 are invalid. Subsequently, when generating themodulated signals addressed to the terminal, the base station (AP)generates and transmits the modulated signal of a single stream.

In addition to the above, for example, consider the cases in whichconstraints like the following exist.

[Constraint Condition 1]

In “communication scheme #B”, assume that with the single-carrierscheme, in the “method that transmits multiple modulated signalsincluding multiple streams using multiple antennas”, the method of“changing the phase of at least one modulated signal among multiplemodulated signals” is not supported (other methods may be supported),and in addition, in the multi-carrier scheme such as OFDM, the method of“changing the phase of at least one modulated signal among multiplemodulated signals” is supported at least (other methods may besupported).

This case becomes like the following.

Example 3

In the case in which terminal #p transmits with the data 3002 set to“01” (that is, supporting only the single-carrier scheme), the basestation (AP) obtaining this data determines that the data 2801 isinvalid. Subsequently, when generating modulated signals addressed toterminal #p, the base station (AP) does not use the method of “changingthe phase of at least one modulated signal among multiple modulatedsignals”.

Note that FIG. 30 is an example of the reception capability notificationsymbols 2702 transmitted by terminal #p. As described using FIG. 30, inthe case in which terminal #p transmits multiple pieces of receptioncapability information (for example, the data 2801, the data 2901, thedata 3001, the data 3002, and the data 3003 in FIG. 30), when the basestation (AP) decides the method of generating modulated signalsaddressed to terminal #p on the basis of the reception capabilitynotification symbols 2702, in some cases the base station (AP) needs todetermine that some of the multiple pieces of reception capabilityinformation is invalid. When such a situation is considered, if terminal#p bundles and transmits the multiple pieces of reception capabilityinformation as the reception capability notification symbols 2702, anadvantageous effect may be obtained in which the base station (AP)decides the generation of the modulated signals addressed to terminal #peasily and with little processing time.

Note that the data structure described in Embodiment 3 is merely oneexample, and the configuration is not limited thereto. Also, the numberof bits in each piece of data and method of settings the bits are notlimited to the example described in Embodiment 3.

Embodiment 4

Embodiment 1, Embodiment 2, and Embodiment 3 describe that both the caseof generating multiple modulated signals including multiple streams andthe case of generating the modulated signal of a single stream arepossible in the user #p signal processor 102_p (where p is an integerfrom 1 to M) in FIG. 1. In Embodiment 4, a different example of the user#p signal processor 102_p at this time will be described.

FIG. 31 is a diagram illustrating an example of a configuration of theuser #p signal processor 102_p. Note that in FIG. 31, parts whichoperate similarly to FIG. 2 are denoted with the same numbers. In FIG.31, since the detailed operation of the signal processor 206 has beendescribed in Embodiment 1, a description is omitted here. In thefollowing, the characteristic operation will be described.

Assume that the control signal 200 includes information about whether touse the “method of transmitting the modulated signal of a single stream”or the “method of transmitting multiple modulated signals includingmultiple streams” in the signal processor for each user.

In the user #p signal processor 102_p, in the case in which generatingmodulated signals by the “method of transmitting multiple modulatedsignals including multiple streams” is specified by the control signal200, the signal processor 206 generates multiple modulated signalsincluding multiple streams, outputs a user #p signal-processed signal206_A to a signal selector 3101, and outputs a user #p signal-processedsignal 206_B to an output controller 3102.

The signal selector 3101 accepts the control signal 200, the user #psignal-processed signal 206_A, and the mapped signal 205_1 as input.Since generating modulated signals by the “method of transmittingmultiple modulated signals including multiple streams” is specified bythe control signal 200, the signal selector 3101 outputs the user #psignal-processed signal 206_A as a selected signal 206_A′. Additionally,the selected signal 206_A′ corresponds to the user #p first basebandsignal 103_p_1 in FIG. 1.

The output controller 3102 accepts the control signal 200 and the user#p signal-processed signal 206_B as input, and since generatingmodulated signals by the “method of transmitting multiple modulatedsignals including multiple streams” is specified by the control signal200, the output controller 3102 outputs the user #p signal-processedsignal 206_B as an output signal 206_B′. Additionally, the output signal206_B′ corresponds to the user #p second baseband signal 103_p_2 in FIG.1.

In the user #p signal processor 102_p, in the case in which generating amodulated signal by the “method of transmitting a modulated signal of asingle stream” is specified by the control signal 200, the signalprocessor 206 does not operate.

Likewise, the mapper 204 does not output the mapped signal 205_2.

The signal selector 3101 accepts the control signal 200, the user #psignal-processed signal 206_A, and the mapped signal 205_1 as input, andsince generating a modulated signal by the “method of transmitting amodulated signal of a single stream” is specified, the signal selector3101 outputs the mapped signal 205_1 as a selected signal 206_A′.Additionally, the selected signal 206_A′ corresponds to the user #pfirst baseband signal 103_p_1 in FIG. 1.

The output controller 3102 accepts the control signal 200 and the user#p signal-processed signal 206_B as input, and since generating amodulated signal by the “method of transmitting a modulated signal of asingle stream” is specified by the control signal 200, the outputcontroller 3102 does not output the output signal 206_B′.

By operating as above, in the user #p signal processor 102_p in FIG. 1,the output of a modulated signal or signals for the case of generatingmultiple modulated signals including multiple streams, or the case ofgenerating a modulated signal of a single stream, may be realized.

It has been described that both the case of generating multiplemodulated signals including multiple streams and the case of generatingthe modulated signal of a single stream are possible in the user #psignal processor 102_p (where p is an integer from 1 to M) in FIG. 1.Herein, an example of the configuration of the user #p signal processor102_p in FIG. 32 different from FIG. 31 will be described.

FIG. 32 is a diagram illustrating an example of a configuration of theuser #p signal processor 102_p. Parts of the configuration which aresimilar to FIGS. 2 and 31 are denoted with the same numbers. In FIG. 32,since the detailed operation of the signal processor 206 has beendescribed in Embodiment 1, a description is omitted here. In thefollowing, the characteristic operation will be described.

Assume that the control signal 200 includes information about whether touse the “method of transmitting the modulated signal of a single stream”or the “method of transmitting multiple modulated signals includingmultiple streams” in the signal processor for each user.

In the user #p signal processor 102_p, in the case in which generatingmodulated signals by the “method of transmitting multiple modulatedsignals including multiple streams” is specified by the control signal200, the signal processor 206 operates, generating multiple modulatedsignals including multiple streams, and outputting user #psignal-processed signals 206_A and 206_B.

The signal selector 3101 accepts the control signal 200, the user #psignal-processed signal 206_A, and a processed signal 3202_1 as input.Since generating modulated signals by the “method of transmittingmultiple modulated signals including multiple streams” is specified bythe control signal 200, the signal selector 3101 outputs the user #psignal-processed signal 206_A as a selected signal 206_A′. Additionally,the selected signal 206_A′ corresponds to the user #p first basebandsignal 103_p_1 in FIG. 1.

The signal selector 3203 accepts the control signal 200, the user #psignal-processed signal 206_B, and a processed signal 3202_2 as input.Since generating modulated signals by the “method of transmittingmultiple modulated signals including multiple streams” is specified bythe control signal 200, the signal selector 3203 outputs the user #psignal-processed signal 206_B as a selected signal 206_B′. Additionally,the selected signal 206_B′ corresponds to the user #p second basebandsignal 103_p_2 in FIG. 1.

In the user #p signal processor 102_p, in the case in which generating amodulated signal by the “method of transmitting a modulated signal of asingle stream” is specified by the control signal 200, the signalprocessor 206 does not operate.

Likewise, the mapper 204 does not output the mapped signal 205_2.

A processor 3201 accepts the control signal 200 and the mapped signal205_1 as input. Since generating modulated signals by the “method oftransmitting a modulated signal of a single stream” is specified by thecontrol signal 200, the processor 3201 generates and outputssignal-processed signals 3202_1 and 3202_2, which correspond to themapped signal 205_1. At this time, assume that the data included in themapped signal 205_1 and the data included in the processed signal 3202_1are the same, and additionally, the data included in the mapped signal205_1 and the data included in the processed signal 3202_2 are the same.

The signal selector 3101 accepts the control signal 200, the user #psignal-processed signal 206_A, and a processed signal 3202_1 as input.Since generating modulated signals by the “method of transmitting amodulated signal of a single stream” is specified by the control signal200, the signal selector 3101 outputs the processed signal 3202_1 as theselected signal 206_A′. Additionally, the selected signal 206_A′corresponds to the user #p first baseband signal 103_p_1 in FIG. 1.

The signal selector 3203 accepts the control signal 200, the user #psignal-processed signal 206_B, and a processed signal 3202_2 as input.Since generating modulated signals by the “method of transmitting amodulated signal of a single stream” is specified by the control signal200, the signal selector 3203 outputs the processed signal 3202_2 as theselected signal 206_B′. Additionally, the selected signal 206_B′corresponds to the user #p second baseband signal 103_p_2 in FIG. 1.

As above, two exemplary configurations are used to describe exemplaryoperation of the case of generating multiple modulated signals includingmultiple streams and the case of generating the modulated signal of asingle stream in the user #p signal processor 102_p (where p is aninteger from 1 to M) in FIG. 1. In the signal processor for each user inFIG. 1, either the generation of multiple modulated signals includingmultiple streams or the generation of the modulated signal of a singlestream as described above may be executed. Also, as described inEmbodiment 1 and the like, a modulated signal may not be output by thesignal processor for a user in FIG. 1 in some cases.

(Supplement 1)

In Formula (1) to Formula (42), formulas which are functions of i (thesymbol number) are included. Additionally, FIGS. 12 to 17 are used todescribe how symbols may be arranged in the time axis direction, thefrequency axis direction, or the time-frequency axis directions.Consequently, in Formula (1) to Formula (42), a formula described as afunction of i may be interpreted as being a function of time,interpreted as a function of frequency, or interpreted as being afunction of time and frequency.

In this specification, for example, it is assumed that the transmissionapparatus in FIG. 1 is capable of generating and transmitting “modulatedsignals using OFDM and modulated signals of a single-carrier scheme in aspecific frequency band”. At this time, in the case in which thetransmission apparatus in FIG. 1 transmits multiple modulated signals(baseband signals) of a certain user, and executes phase change asdescribed in this specification, the period of the phase change whenOFDM is used may be set differently from the period of the phase changewhen the single-carrier scheme is used. Since the frame configurationsare different, setting different periods is favorable in some cases.However, the period of phase change when using OFDM and the period ofphase change when using the single-carrier scheme may also be the same.

Also, the user #1 signal processor 102_1 to the user #M signal processor102_M in FIG. 1 may generate single-carrier modulated signals ormulti-carrier modulated signals like OFDM, for example. Consequently,the single-carrier modulated signals and the multi-carrier modulatedsignals like OFDM may be transmitted from the transmission apparatus ofFIG. 1 using identical times and identical frequencies (frequency bandsthat overlap with each other at least partially).

For example, in the user #1 signal processor 102_1, the user #1 firstbaseband signal 103_1_1 corresponding to a modulated signal of thesingle-carrier scheme and the user #1 second baseband signal 103_1_2corresponding to a modulated signal of the single-carrier scheme aregenerated, while in the user #2 signal processor 102_2, the user #2first baseband signal 103_2_1 corresponding to a modulated signal of themulti-carrier scheme like OFDM and the user #2 second baseband signal103_2_2 corresponding to a modulated signal of the multi-carrier schemelike OFDM are generated, and the transmission apparatus in FIG. 1 maytransmit “the user #1 first baseband signal 103_1_1 corresponding to amodulated signal of the single-carrier scheme and the user #1 secondbaseband signal 103_1_2 corresponding to a modulated signal of thesingle-carrier scheme” and the “user #2 first baseband signal 103_2_1corresponding to a modulated signal of the multi-carrier scheme likeOFDM and the user #2 second baseband signal 103_2_2 corresponding to amodulated signal of the multi-carrier scheme like OFDM” at identicaltimes and identical frequencies (frequency bands that overlap with eachother at least partially). At this time, it is sufficient for the “user#1 first baseband signal 103_1_1 corresponding to a modulated signal ofthe single-carrier scheme and the user #1 second baseband signal 103_1_2corresponding to a modulated signal of the single-carrier scheme” to bebaseband signals generated by any of the methods of “performingprecoding and phase change”, “performing precoding”, “performing phasechange without precoding”, and “not performing precoding or phasechange”. Similarly, it is sufficient for the “user #2 first basebandsignal 103_2_1 corresponding to a modulated signal of the multi-carrierscheme like OFDM and the user #2 second baseband signal 103_2_2corresponding to a modulated signal of the multi-carrier scheme likeOFDM” to be baseband signals generated by any of the methods of“performing precoding and phase change”, “performing precoding”,“performing phase change without precoding”, and “not performingprecoding or phase change”.

As another example, in the user #1 signal processor 102_1, the basebandsignal of a single stream of the single-carrier scheme is generated,while in the user #2 signal processor 102_2, the user #2 first basebandsignal 103_2_1 corresponding to a modulated signal of the multi-carrierscheme like OFDM and the user #2 second baseband signal 103_2_2corresponding to a modulated signal of the multi-carrier scheme likeOFDM are generated, and the transmission apparatus in FIG. 1 maytransmit the “baseband signal of a single stream of the single-carrierscheme” and the “user #2 first baseband signal 103_2_1 corresponding toa modulated signal of the multi-carrier scheme like OFDM and the user #2second baseband signal 103_2_2 corresponding to a modulated signal ofthe multi-carrier scheme like OFDM” at identical times and identicalfrequencies (frequency bands that overlap with each other at leastpartially). At this time, it is sufficient for the “user #2 firstbaseband signal 103_2_1 corresponding to a modulated signal of themulti-carrier scheme like OFDM and the user #2 second baseband signal103_2_2 corresponding to a modulated signal of the multi-carrier schemelike OFDM” to be baseband signals generated by any of the methods of“performing precoding and phase change”, “performing precoding”,“performing phase change without precoding”, and “not performingprecoding or phase change”.

Also, as another example, in the user #1 signal processor 102_1, theuser #1 first baseband signal 103_1_1 corresponding to a modulatedsignal of the single-carrier scheme and the user #1 second basebandsignal 103_1_2 corresponding to a modulated signal of the single-carrierscheme are generated, while in the user #2 signal processor 102_2, thebaseband signal of a single stream of the multi-carrier scheme like OFDMis generated, and the transmission apparatus in FIG. 1 may transmit “theuser #1 first baseband signal 103_1_1 corresponding to a modulatedsignal of the single-carrier scheme and the user #1 second basebandsignal 103_1_2 corresponding to a modulated signal of the single-carrierscheme” and the “baseband signal of a single stream of the multi-carrierscheme such as OFDM” at identical times and identical frequencies(frequency bands that overlap with each other at least partially). Atthis time, it is sufficient for the “user #2 first baseband signal103_2_1 corresponding to a modulated signal of the multi-carrier schemelike OFDM and the user #2 second baseband signal 103_2_2 correspondingto a modulated signal of the multi-carrier scheme like OFDM” to bebaseband signals generated by any of the methods of “performingprecoding and phase change”, “performing precoding”, “performing phasechange without precoding”, and “not performing precoding or phasechange”.

Furthermore, as another example, in the user #1 signal processor 102_1,the baseband signal of a single stream of the single-carrier scheme isgenerated, while in the user #2 signal processor 102_2, the basebandsignal of a single stream of the multi-carrier scheme like OFDM isgenerated, and the transmission apparatus in FIG. 1 may transmit“baseband signal of a single stream of the single-carrier scheme” andthe “baseband signal of a single stream of the multi-carrier scheme suchas OFDM” at identical times and identical frequencies (frequency bandsthat overlap with each other at least partially).

Also, FIGS. 2 and 31 illustrate a configuration in which the signalprocessor for each other is provided with a single error-correctingcoder and a single mapper, but the configuration is not limited thereto.For example, it is also possible to take a configuration in which afirst error-correcting coder and a first mapper are provided to generatethe user #p mapped signal (baseband signal) 205_1 for transmitting firstdata, while a second error-correcting coder and a second mapper areprovided to generate the user #p mapped signal (baseband signal) 205_2for transmitting second data. Also, the numbers of error-correctingcoders and mappers may each be three or more.

Embodiment 5

In the present embodiment, the example described in Embodiment 3 will beused to describe the exemplary operation of a terminal. FIG. 34 is adiagram illustrating an example of a configuration of the terminal #p onthe other end of communication with the base station in FIG. 24.Terminal #p includes a transmission apparatus 3403, a receptionapparatus 3404, and a control signal generator 3408.

The transmission apparatus 3403 accepts data 3401, a signal group 3402,and a control signal 3409 as input. The transmission apparatus 3403generates a modulated signal corresponding to the data 3401 and thesignal group 3402, and transmits the modulated signal from an antenna.

The reception apparatus 3404 receives a modulated signal transmittedfrom the other end of communication, such as a base station, forexample, executes signal processing, demodulation, and decoding on themodulated signal, and outputs a control information signal 3405 andreceived data 3406 from the other end of communication.

The control signal generator 3408 accepts the control information signal3405 from the other end of communication and a setting signal 3407 asinput. On the basis of this information, the control signal generator3408 generates and outputs the control signal 3409 to the transmissionapparatus 3403.

FIG. 35 is a diagram illustrating an example of a configuration of thereception apparatus 3404 of the terminal #p illustrated in FIG. 34. Thereception apparatus 3404 includes an antenna section 3501, a radiosection 3503, a channel estimator 3505, a signal processor 3509, and acontrol information decoder 3507.

The radio section 3503 accepts a received signal 3502 received by theantenna section 3501 as input. The radio section 3503 executesprocessing such as frequency conversion on the received signal 3502, andgenerates a baseband signal 3504. The radio section 3503 outputs thebaseband signal 3504 to the channel estimator 3505, the controlinformation decoder 3507, and the signal processor 3509.

The control information decoder 3507 accepts the baseband signal 3504 asinput. The control information decoder 3507 outputs control information3508 obtained by demodulating control information symbols included inthe baseband signal 3504.

The channel estimator 3505 accepts the baseband signal 3504 as input.The channel estimator 3505 extracts a preamble and pilot symbolsincluded in the baseband signal 3504. The channel estimator 3505estimates channel variation on the basis of the preamble and the pilotsymbols, and generates a channel estimation signal 3506 indicating theestimated channel variation. The channel estimator 3505 outputs thechannel estimation signal 3506 to the signal processor 3509.

The signal processor 3509 accepts the baseband signal 3504, the channelestimation signal 3506, and the control information 3508 as input. Onthe basis of the channel estimation signal 3506 and the controlinformation 3508, the signal processor 3509 executes demodulation anderror-correcting decoding on data symbols included in the basebandsignal 3504, and generates received data 3510. The signal processor 3509outputs the received data 3510.

FIG. 36 is a diagram illustrating an example of a frame configuration ofa modulated signal of a single stream transmitted using a multi-carriertransmission scheme such as OFDM. In FIG. 36, the horizontal axis isfrequency, and the vertical axis is time. FIG. 36 illustrates, as oneexample, symbols from carrier 1 to carrier 36. Also, FIG. 36 illustratessymbols from time 1 to time 11. The frame configuration illustrated inFIG. 36 is an example of a frame configuration of a modulated signal ofa single stream transmitted using a multi-carrier transmission schemesuch as OFDM by the base station (AP) on the other end of communicationwith terminal #p.

In FIG. 36, 3601 are pilot symbols, 3602 are data symbols, and 3603 areother symbols. The pilot symbols 3601 are taken to be symbols by whichterminal #p estimates the channel variation. The data symbols 3602 aretaken to be symbols by which the base station or AP transmits data toterminal #p. The other symbols 3603 are taken to include, for example,symbols by which terminal #p executes frequency offset estimation,frequency synchronization, and time synchronization, and/or controlinformation symbols for demodulating the data symbols 3602 (such asinformation related to the transmission method, the modulation scheme,and the error-correcting coding method of the data symbols 3602).

Additionally, for example, the transmission apparatus of the basestation illustrated in FIG. 1 or 24 may also transmit a modulated signalof a single stream with the frame configuration in FIG. 36 to terminal#p.

FIG. 37 is a diagram illustrating an example of a frame configuration ofa modulated signal of a single stream transmitted using a single-carriertransmission scheme. Note that in FIG. 37, the parts of theconfiguration which are similar to FIG. 10 are denoted with the samenumbers. In FIG. 37, the horizontal axis is time, and FIG. 37illustrates symbols from time t1 to t22. The frame configurationillustrated in FIG. 37 is an example of a frame configuration of amodulated signal of a single stream transmitted using a single-carriertransmission scheme by the base station or AP on the other end ofcommunication with terminal #p.

Additionally, for example, the transmission apparatus of the basestation illustrated in FIG. 1 or 24 may also transmit to terminal #p amodulated signal of a single stream with the frame configuration in FIG.37.

Additionally, for example, the transmission apparatus of the basestation illustrated in FIG. 1 or 24 may also transmit to terminal #pmultiple modulated signals of multiple streams with the frameconfiguration in FIG. 8 or 9.

Furthermore, for example, the transmission apparatus of the base stationillustrated in FIG. 1 or 24 may also transmit to terminal #p multiplemodulated signals of multiple streams with the frame configuration inFIG. 10 or 11.

Next, the reception capability in the reception apparatus of terminal #pillustrated in FIG. 35, or in other words, the schemes supported by thereception apparatus, and the processes of terminal #p and the processesof the base station (AP) based on the supported schemes will bedescribed below by citing first to tenth examples.

First Example

As the first example, suppose that the configuration of the receptionapparatus of terminal #p is the configuration illustrated in FIG. 35,and the reception apparatus of terminal #p supports the following.

-   -   The reception, for example, of “communication scheme #A”        described in Embodiment 3 is supported.    -   Consequently, even if the other end of communication transmits        multiple modulated signals of multiple streams, terminal #p does        not support the reception of such signals.    -   Thus, in the case in which the other end of communication        performs phase change when transmitting multiple modulated        signals of multiple streams, terminal #p does not support the        reception of such signals.    -   Only the single-carrier scheme is supported.    -   As the error-correcting coding scheme, only the decoding of        “error-correcting coding scheme #C” is supported.

Thus, terminal #p having the configuration of FIG. 35 supporting theabove generates the reception capability notification symbols 2702illustrated in FIG. 30 on the basis of the rules described in Embodiment3, and transmits the reception capability notification symbols 2702 byfollowing the procedure in FIG. 27, for example.

At this time, terminal #p generates the reception capabilitynotification symbols 2702 illustrated in FIG. 30 in the transmissionapparatus 3403 of FIG. 34, for example. Additionally, following theprocedure in FIG. 27, the transmission apparatus 3403 of FIG. 34transmits the reception capability notification symbols 2702 illustratedin FIG. 30.

The signal processor 155 of the base station (AP) in FIG. 22 acquires abaseband signal group 154 including the reception capabilitynotification symbols 2702 transmitted by terminal #p through thereception antenna group 151 and the radio section group 153.Additionally, the signal processor 155 of the base station (AP) in FIG.22 extracts the data included in the reception capability notificationsymbols 2702, and learns that terminal #p supports the “communicationscheme #A” from the data 3001 related to “supported schemes” (see FIG.30).

Consequently, since the data 2801 related to “demodulation of modulatedsignal with phase change supported/unsupported” in FIG. 30 is invalid,and the communication scheme #A is supported, the signal processor 155of the base station decides not to transmit a phase-changed modulatedsignal, and outputs control information 157 (see FIG. 22) including thisinformation. This is because the communication scheme #A does notsupport the transmitting and receiving of multiple modulated signals formultiple streams.

Also, since the data 2901 related to “reception for multiple streamssupported/unsupported” in FIG. 30 is invalid, and the communicationscheme #A is supported, the signal processor 155 of the base stationdecides not to transmit multiple modulated signals for multiple streams,and outputs a control signal 157 including this information. This isbecause the communication scheme #A does not support the transmittingand receiving of multiple modulated signals for multiple streams.

Additionally, since the data 3003 related to “supported error-correctingcoding schemes” in FIG. 30 is invalid, and the communication scheme #Ais supported, the signal processor 155 of the base station decides touse “error-correcting coding scheme #C”, and outputs a control signal157 including this information. This is because the communication scheme#A supports the “error-correcting coding scheme #C”.

For example, as in FIG. 35, the “communication scheme #A” is supported,and consequently, by having the base station or AP execute operations asdescribed above to not transmit multiple modulated signals for multiplestreams, the base station (AP) appropriately transmits a modulatedsignal of the “communication scheme #A”, and an advantageous effect ofimproving the data transmission efficiency in the system including thebase station (AP) and the terminal #p may be obtained.

Second Example

As the second example, suppose that the configuration of the receptionapparatus of terminal #p is the configuration illustrated in FIG. 35,and the reception apparatus of terminal #p supports the following.

-   -   The receiving, for example, of “communication scheme #B”        described in Embodiment 3 is supported.    -   Since the reception apparatus adopts the configuration        illustrated in FIG. 35, even if the other end of communication        transmits multiple modulated signals of multiple streams,        terminal #p does not support the reception of such signals.    -   Thus, in the case in which the other end of communication        performs phase change when transmitting multiple modulated        signals of multiple streams, terminal #p does not support the        reception of such signals.    -   The single-carrier scheme and the multi-carrier scheme such as        OFDM are supported.    -   As the error-correcting coding scheme, the decoding of        “error-correcting coding scheme #C” and “error-correcting coding        scheme #D” is supported.

Thus, terminal #p having the configuration of FIG. 35 supporting theabove generates the reception capability notification symbols 2702illustrated in FIG. 30 on the basis of the rules described in Embodiment3, and transmits the reception capability notification symbols 2702 byfollowing the procedure in FIG. 27, for example.

At this time, terminal #p generates the reception capabilitynotification symbols 2702 illustrated in FIG. 30 in the transmissionapparatus 3403 of FIG. 34, for example. Additionally, following theprocedure in FIG. 27, the transmission apparatus 3403 of FIG. 34transmits the reception capability notification symbols 2702 illustratedin FIG. 30.

The signal processor 155 of the base station (AP) in FIG. 22 acquires abaseband signal group 154 including the reception capabilitynotification symbols 2702 transmitted by terminal #p through thereception antenna group 151 and the radio section group 153.Additionally, the signal processor 155 of the base station (AP) in FIG.22 extracts the data included in the reception capability notificationsymbols 2702, and learns that terminal #p supports the “communicationscheme #B” from the data 3001 related to “supported schemes”.

Also, from the data 2901 related to “reception for multiple streamssupported/unsupported” in FIG. 30, the signal processor 155 of the basestation learns that terminal #p on the other end of communication isunable to demodulate multiple modulated signals for multiple streams.

Consequently, since the data 2801 related to “demodulation of modulatedsignal with phase change supported/unsupported” in FIG. 30 is invalid,the signal processor 155 of the base station decides not to transmit aphase-changed modulated signal, and outputs control information 157including this information. This is because terminal #p does not support“reception for multiple streams”.

Also, from the data 3002 related to “multi-carrier schemesupported/unsupported” in FIG. 30, the signal processor 155 of the basestation outputs control information 157 including information related tothe terminal #p on the other end of communication supporting amulti-carrier scheme and/or supporting a single-carrier scheme.

Additionally, from the data 3003 related to “supported error-correctingcoding schemes” in FIG. 30, the signal processor 155 of the base stationoutputs control information 157 including information related to theterminal #p on the other end of communication supporting“error-correcting coding scheme #C” and/or “error-correcting codingscheme #D”.

Consequently, by having the base station (AP) execute operations asdescribed above to not transmit multiple modulated signals for multiplestreams, the base station (AP) is able to transmit a modulated signal ofa single stream appropriately, and with this arrangement, anadvantageous effect of improving the data transmission efficiency in thesystem including the base station (AP) and the terminal #p may beobtained.

Third Example

As the third example, suppose that the configuration of the receptionapparatus of terminal #p is the configuration illustrated in FIG. 35,and the reception apparatus of terminal #p supports the following.

-   -   The reception of “communication scheme #A” and the reception of        “communication scheme #B” described in Embodiment 3 are        supported.    -   In both “communication scheme #A” and “communication scheme #B”,        even if the other end of communication transmits multiple        modulated signals of multiple streams, terminal #p does not        support the reception of such signals.    -   Thus, in the case in which the other end of communication        performs phase change when transmitting multiple modulated        signals of multiple streams, terminal #p does not support the        reception of such signals.    -   In both “communication scheme #A” and “communication scheme #B”,        only the single-carrier scheme is supported.    -   Regarding the error-correcting coding schemes, for        “communication scheme #A”, the decoding of “error-correcting        coding scheme #C” is supported, and for “communication scheme        #B”, the decoding of “error-correcting coding scheme #C” and        “error-correcting coding scheme #D” is supported.

Thus, terminal #p having the configuration of FIG. 35 supporting theabove generates the reception capability notification symbols 2702illustrated in FIG. 30 on the basis of the rules described in Embodiment3, and transmits the reception capability notification symbols 2702 byfollowing the procedure in FIG. 27, for example.

At this time, terminal #p generates the reception capabilitynotification symbols 2702 illustrated in FIG. 30 in the transmissionapparatus 3403 of FIG. 34, for example. Additionally, following theprocedure in FIG. 27, the transmission apparatus 3403 of FIG. 34transmits the reception capability notification symbols 2702 illustratedin FIG. 30.

The signal processor 155 of the base station (AP) in FIG. 22 acquires abaseband signal group 154 including the reception capabilitynotification symbols 2702 transmitted by terminal #p through thereception antenna group 151 and the radio section group 153.Additionally, the signal processor 155 of the base station (AP) in FIG.22 extracts the data included in the reception capability notificationsymbols 2702, and learns that terminal #p supports the “communicationscheme #A” and the “communication scheme #B” from the data 3001 relatedto “supported schemes”.

Additionally, from the data 2901 related to “reception for multiplestreams supported/unsupported” in FIG. 30, the signal processor 155 ofthe base station learns that terminal #p “does not support reception formultiple streams”.

Consequently, since the data 2801 related to “demodulationsupported/unsupported when using phase change” in FIG. 30 is invalid,and the communication scheme #A is supported, the signal processor 155of the base station decides not to transmit a phase-changed modulatedsignal, and outputs control information 157 including this information.This is because terminal #p does not support the transmitting andreceiving of multiple modulated signals for multiple streams.

Additionally, from the data 3002 related to “multi-carrier schemesupported/unsupported” in FIG. 30, the signal processor 155 of the basestation learns whether terminal #p supports the single-carrier schemeand whether terminal #p supports the multi-carrier scheme such as OFDM.

Also, from the data 3003 related to “supported error-correcting codingschemes” in FIG. 30, the signal processor 155 of the base station learnsthat terminal #p supports the decoding of “error-correcting codingscheme #C” and “error-correcting coding scheme #D”.

Consequently, by having the base station (AP) execute operations asdescribed above to not transmit multiple modulated signals for multiplestreams, the base station (AP) is able to transmit a modulated signal ofa single stream appropriately, and with this arrangement, anadvantageous effect of improving the data transmission efficiency in thesystem including the base station (AP) and the terminal #p may beobtained.

Fourth Example

As the fourth example, suppose that the configuration of the receptionapparatus of terminal #p is the configuration illustrated in FIG. 35,and the reception apparatus of terminal #p supports the following.

-   -   The reception of “communication scheme #A” and the reception of        “communication scheme #B” described in Embodiment 3 are        supported.    -   In both “communication scheme #A” and “communication scheme #B”,        even if the other end of communication transmits multiple        modulated signals of multiple streams, terminal #p does not        support the reception of such signals.    -   Thus, in the case in which the other end of communication        performs phase change when transmitting multiple modulated        signals of multiple streams, terminal #p does not support the        reception of such signals.    -   For “communication scheme #A”, the single-carrier scheme is        supported, and for “communication scheme #B”, the single-carrier        scheme and the multi-carrier scheme such as OFDM is supported.    -   Regarding the error-correcting coding schemes, for        “communication scheme #A”, the decoding of “error-correcting        coding scheme #C” is supported, and for “communication scheme        #B”, the decoding of “error-correcting coding scheme #C” and        “error-correcting coding scheme #D” is supported.

Thus, terminal #p having the configuration of FIG. 35 supporting theabove generates the reception capability notification symbols 2702illustrated in FIG. 30 on the basis of the rules described in Embodiment3, and transmits the reception capability notification symbols 2702 byfollowing the procedure in FIG. 27, for example.

The signal processor 155 of the base station (AP) in FIG. 22 acquires abaseband signal group 154 including the reception capabilitynotification symbols 2702 transmitted by terminal #p through thereception antenna group 151 and the radio section group 153.Additionally, the signal processor 155 of the base station (AP) in FIG.22 extracts the data included in the reception capability notificationsymbols 2702, and learns that terminal #p supports the “communicationscheme #A” and the “communication scheme #B” from the data 3001 relatedto “supported schemes”.

Additionally, from the data 2901 related to “reception for multiplestreams supported/unsupported” in FIG. 30, the signal processor 155 ofthe base station learns that terminal #p “does not support reception formultiple streams”.

Consequently, since the data 2801 related to “demodulation of modulatedsignal with phase change supported/unsupported” in FIG. 30 is invalid,and the communication scheme #A is supported, the signal processor 155of the base station decides not to transmit a phase-changed modulatedsignal, and outputs control information 157 including this information.This is because terminal #p does not support the transmitting andreception of multiple modulated signals for multiple streams.

Additionally, from the data 3002 related to “multi-carrier schemesupported/unsupported” in FIG. 30, the signal processor 155 of the basestation learns whether terminal #p supports the single-carrier schemeand whether terminal #p supports the multi-carrier scheme such as OFDM.

At this time, the data 3002 related to “multi-carrier schemesupported/unsupported” needs a configuration like the one describedbelow, for example.

Assume that the data 3002 related to “multi-carrier schemesupported/unsupported” is made up of 4 bits, and the 4 bits areexpressed as g0, g1, g2, and g3. At this time, terminal #p sets g0, g1,g2, and g3 as follows according to the reception capability of terminal#p, and transmits the data 3002 related to “multi-carrier schemesupported/unsupported”.

For the “communication scheme #A”, in the case in which terminal #psupports demodulation of the single-carrier scheme, terminal #p sets(g0, g1)=(0, 0).

For the “communication scheme #A”, in the case in which terminal #psupports demodulation of the multi-carrier scheme such as OFDM, terminal#p sets (g0, g1)=(0, 1).

For the “communication scheme #A”, in the case in which terminal #psupports demodulation of the multi-carrier scheme such as OFDM, terminal#p sets (g0, g1)=(1, 1).

For the “communication scheme #B”, in the case in which terminal #psupports demodulation of the single-carrier scheme, terminal #p sets(g2, g3)=(0, 0).

For the “communication scheme #B”, in the case in which terminal #psupports demodulation of the multi-carrier scheme such as OFDM, terminal#p sets (g2, g3)=(0, 1).

For the “communication scheme #B”, in the case in which terminal #psupports demodulation of the multi-carrier scheme such as OFDM, terminal#p sets (g2, g3)=(1, 1).

Also, from the data 3003 related to “supported error-correcting codingschemes” in FIG. 30, the signal processor 155 of the base station learnsthat terminal #p supports the decoding of “error-correcting codingscheme #C” and “error-correcting coding scheme #D”.

Consequently, by having the base station (AP) execute operations asdescribed above to not transmit multiple modulated signals for multiplestreams, the base station (AP) is able to transmit a modulated signal ofa single stream appropriately, and with this arrangement, anadvantageous effect of improving the data transmission efficiency in thesystem including the base station (AP) and the terminal #p may beobtained.

Fifth Example

As the fifth example, suppose that the configuration of the receptionapparatus of terminal #p is the configuration illustrated in FIG. 19,and the reception apparatus of terminal #p supports the following, forexample.

-   -   The reception, for example, of “communication scheme #A” and        “communication scheme #B” described in Embodiment 3 is        supported.    -   If the other end of communication transmits multiple modulated        signals of multiple streams in “communication scheme #B”,        terminal #p supports the reception of such signals. Also, in        “communication scheme #A” and “communication scheme #B”, if the        other end of communication transmits a modulated signal of a        single stream, terminal #p supports the reception of such a        signal.    -   Additionally, in the case in which the other end of        communication performs phase change when transmitting modulated        signals of multiple streams, terminal #p supports the reception        of such signals.    -   Only the single-carrier scheme is supported.    -   As the error-correcting coding scheme, only the decoding of        “error-correcting coding scheme #C” is supported.

Thus, terminal #p having the configuration of FIG. 19 supporting theabove generates the reception capability notification symbols 2702illustrated in FIG. 30 on the basis of the rules described in Embodiment3, and transmits the reception capability notification symbols 2702 byfollowing the procedure in FIG. 27, for example.

At this time, terminal #p generates the reception capabilitynotification symbols 2702 illustrated in FIG. 30 with the transmissionapparatus 3403 in FIG. 34, for example, and following the procedure inFIG. 27, the transmission apparatus 3403 of FIG. 34 transmits thereception capability notification symbols 2702 illustrated in FIG. 30.

The signal processor 155 of the base station (AP) in FIG. 22 acquires abaseband signal group 154 including the reception capabilitynotification symbols 2702 transmitted by terminal #p through thereception antenna group 151 and the radio section group 153.Additionally, the signal processor 155 of the base station (AP) in FIG.22 extracts the data included in the reception capability notificationsymbols 2702, and learns that terminal #p supports the “communicationscheme #A” and the “communication scheme #B” from the data 3001 relatedto “supported schemes”.

Also, from the data 2901 related to “reception for multiple streamssupported/unsupported” in FIG. 30, the signal processor 155 of the basestation learns that “if the other end of communication transmitsmultiple modulated signals of multiple streams “communication scheme#B”, terminal #p supports the reception of such signals”. Also, from thedata 2901 related to “reception for multiple streamssupported/unsupported” in FIG. 30, the signal processor 155 of the basestation learns that “if the other end of communication transmits amodulated signal of a single stream in “communication scheme #A” and“communication scheme #B”, terminal #p supports the reception of such asignal”.

Additionally, from the data 2801 related to “demodulation of modulatedsignal with phase change supported/unsupported” in FIG. 30, the signalprocessor 155 of the base station learns that terminal #p “supportsdemodulation of modulated signal with phase change”.

From the data 3002 related to “multi-carrier schemesupported/unsupported” in FIG. 30, the signal processor 155 of the basestation learns that terminal #p “supports the single-carrier schemeonly”.

From the data 3003 related to “supported error-correcting codingschemes” in FIG. 30, the signal processor 155 of the base station learnsthat terminal #p supports the decoding of “error-correcting codingscheme #C” only.

Consequently, by having the base station (AP) take into account thecommunication schemes supported by terminal #p, the communicationenvironment, and the like, and by having the base station (AP)appropriately generate and transmit modulated signals receivable byterminal #p, an advantageous effect of improving the data transmissionefficiency in the system including the base station (AP) and theterminal #p may be obtained.

Sixth Example

As the sixth example, suppose that the configuration of the receptionapparatus of terminal #p is the configuration illustrated in FIG. 19,and the reception apparatus of terminal #p supports the following, forexample.

-   -   The reception, for example, of “communication scheme #A” and        “communication scheme #B” described in Embodiment 3 is        supported.    -   If the other end of communication transmits multiple modulated        signals of multiple streams in “communication scheme #B”,        terminal #p supports the reception of such signals. Also, in        “communication scheme #A” and “communication scheme #B”, if the        other end of communication transmits a modulated signal of a        single stream, terminal #p supports the reception of such a        signal.    -   Additionally, in the case in which the other end of        communication performs phase change when transmitting modulated        signals of multiple streams, terminal #p does not support the        reception of such signals.    -   Only the single-carrier scheme is supported.    -   As the error-correcting coding scheme, the decoding of        “error-correcting coding scheme #C” and the decoding of        “error-correcting coding scheme #D” are supported.

Thus, terminal #p having the configuration of FIG. 19 supporting theabove generates the reception capability notification symbols 2702illustrated in FIG. 30 on the basis of the rules described in Embodiment3, and transmits the reception capability notification symbols 2702 byfollowing the procedure in FIG. 27, for example.

At this time, terminal #p generates the reception capabilitynotification symbols 2702 illustrated in FIG. 30 with the transmissionapparatus 3403 in FIG. 34, for example, and following the procedure inFIG. 27, the transmission apparatus 3403 of FIG. 34 transmits thereception capability notification symbols 2702 illustrated in FIG. 30.

The signal processor 155 of the base station (AP) in FIG. 22 acquires abaseband signal group 154 including the reception capabilitynotification symbols 2702 transmitted by terminal #p through thereception antenna group 151 and the radio section group 153.Additionally, the signal processor 155 of the base station (AP) in FIG.22 extracts the data included in the reception capability notificationsymbols 2702, and learns that terminal #p supports the “communicationscheme #A” and the “communication scheme #B” from the data 3001 relatedto “supported schemes”.

Also, from the data 2901 related to “reception for multiple streamssupported/unsupported” in FIG. 30, the signal processor 155 of the basestation learns that “if the other end of communication transmitsmultiple modulated signals of multiple streams with terminal #p in“communication scheme #B”, terminal #p supports the reception of suchsignals”. Also, from the data 2901 related to “reception for multiplestreams supported/unsupported” in FIG. 30, the signal processor 155 ofthe base station learns that “if the other end of communicationtransmits a modulated signal of a single stream in “communication scheme#A” and “communication scheme #B”, terminal #p supports the reception ofsuch a signal”.

Additionally, from the data 2801 related to “demodulation of modulatedsignal with phase change supported/unsupported” in FIG. 30, the signalprocessor 155 of the base station learns that terminal #p “does notsupport demodulation of modulated signal with phase change.”Consequently, when transmitting multiple modulated signals of multiplestreams to the terminal #p, the base station (AP) transmits themodulated signals without performing phase change.

From the data 3002 related to “multi-carrier schemesupported/unsupported” in FIG. 30, the signal processor 155 of the basestation learns that terminal #p “supports the single-carrier schemeonly”.

From the data 3003 related to “supported error-correcting codingschemes” in FIG. 30, the signal processor 155 of the base station learnsthat terminal #p “supports the decoding of ‘error-correcting codingscheme #C’ and the decoding of ‘error-correcting coding scheme #D’”.

Consequently, by having the base station (AP) take into account thecommunication schemes supported by terminal #p, the communicationenvironment, and the like, and by having the base station (AP)appropriately generate and transmit modulated signals receivable byterminal #p, an advantageous effect of improving the data transmissionefficiency in the system including the base station (AP) and theterminal #p may be obtained.

Seventh Example

As the seventh example, suppose that the configuration of the receptionapparatus of terminal #p is the configuration illustrated in FIG. 19,and the reception apparatus of terminal #p supports the following, forexample.

-   -   The reception, for example, of “communication scheme #A” and        “communication scheme #B” described in Embodiment 3 is        supported.    -   If the other end of communication transmits multiple modulated        signals of multiple streams in “communication scheme #B”,        terminal #p supports the reception of such signals. Also, in        “communication scheme #A” and “communication scheme #B”, if the        other end of communication transmits a modulated signal of a        single stream, terminal #p supports the reception of such a        signal.    -   For “communication scheme #A”, the single-carrier scheme is        supported, and for “communication scheme #B”, the single-carrier        scheme and the multi-carrier scheme such as OFDM is supported.        However, assume that “the other end of communication is able to        perform phase change when transmitting modulated signals of        multiple streams” only in the case of the multi-carrier scheme        such as OFDM of “communication scheme #B”.    -   Additionally, in the case in which the other end of        communication performs phase change when transmitting modulated        signals of multiple streams, terminal #p supports the reception        of such signals.    -   As the error-correcting coding scheme, the decoding of        “error-correcting coding scheme #C” and the decoding of        “error-correcting coding scheme #D” are supported.

Thus, terminal #p having the configuration of FIG. 19 supporting theabove generates the reception capability notification symbols 2702illustrated in FIG. 30 on the basis of the rules described in Embodiment3 and in the present embodiment, and transmits the reception capabilitynotification symbols 2702 by following the procedure in FIG. 27, forexample.

At this time, terminal #p generates the reception capabilitynotification symbols 2702 illustrated in FIG. 30 with the transmissionapparatus 3403 in FIG. 34, for example, and following the procedure inFIG. 27, the transmission apparatus 3403 of FIG. 34 transmits thereception capability notification symbols 2702 illustrated in FIG. 30.

The signal processor 155 of the base station (AP) in FIG. 22 acquires abaseband signal group 154 including the reception capabilitynotification symbols 2702 transmitted by terminal #p through thereception antenna group 151 and the radio section group 153.Additionally, the signal processor 155 of the base station (AP) in FIG.22 extracts the data included in the reception capability notificationsymbols 2702, and learns that terminal #p supports the “communicationscheme #A” and the “communication scheme #B” from the data 3001 relatedto “supported schemes”.

Also, from the data 2901 related to “reception for multiple streamssupported/unsupported” in FIG. 30, the signal processor 155 of the basestation learns that “if the other end of communication transmitsmultiple modulated signals of multiple streams with terminal #p in“communication scheme #B”, terminal #p supports the reception of suchsignals”. Also, from the data 2901 related to “reception for multiplestreams supported/unsupported” in FIG. 30, the signal processor 155 ofthe base station learns that “if the other end of communicationtransmits a modulated signal of a single stream in “communication scheme#A” and “communication scheme #B”, terminal #p supports the reception ofsuch a signal”.

Additionally, from the data 2801 related to “demodulation of modulatedsignal with phase change supported/unsupported” in FIG. 30, the signalprocessor 155 of the base station learns that terminal #p “does notsupport phase modulation demodulation”. Consequently, when transmittingmultiple modulated signals of multiple streams to the terminal #p, thebase station (AP) transmits the modulated signals without performingphase change. Note that when terminal #p obtains information indicating“demodulation of modulated signal with phase change supported” in thedata 2801 related to “demodulation of modulated signal with phase changesupported/unsupported” as described above, terminal #p understands thatthis applies only to “communication scheme #B”.

From the data 3002 related to “multi-carrier schemesupported/unsupported” in FIG. 30, the signal processor 155 of the basestation learns that terminal #p supports the single-carrier scheme as“communication scheme #A”, and supports the single-carrier scheme andthe multi-carrier scheme such as OFDM as “communication scheme #B”. Atthis time, as described above, terminal #p preferably is configured tonotify the base station or AP of the conditions of support for thesingle-carrier scheme and the multi-carrier scheme such as OFDM in“communication scheme #A”, and support for the single-carrier scheme andthe multi-carrier scheme such as OFDM in “communication scheme #B”.

From the data 3003 related to “supported error-correcting codingschemes” in FIG. 30, the signal processor 155 of the base station learnsthat terminal #p “supports the decoding of ‘error-correcting codingscheme #C’ and the decoding of ‘error-correcting coding scheme #D’”.

Consequently, by having the base station (AP) take into account thecommunication schemes supported by terminal #p, the communicationenvironment, and the like, and by having the base station (AP)appropriately generate and transmit modulated signals receivable byterminal #p, an advantageous effect of improving the data transmissionefficiency in the system including the base station (AP) and theterminal #p may be obtained.

Eighth Example

As the eighth example, suppose that the configuration of the receptionapparatus of terminal #p is the configuration illustrated in FIG. 19,and the receiving apparatus of terminal #p supports the following, forexample.

-   -   The reception, for example, of “communication scheme #A” and        “communication scheme #B” described in Embodiment 3 is        supported.    -   If the other end of communication transmits multiple modulated        signals of multiple streams in “communication scheme #B”,        terminal #p supports the reception of such signals. Also, in        “communication scheme #A” and “communication scheme #B”, if the        other end of communication transmits a modulated signal of a        single stream, terminal #p supports the reception of such a        signal.    -   Additionally, in the case of the single-carrier scheme of        “communication scheme #B”, if the other end of communication        transmits multiple modulated signals of multiple streams,        terminal #p supports the reception of such signals.    -   On the other hand, assume that in the case of the multi-carrier        scheme such as OFDM of “communication scheme #B”, if the other        end of communication transmits multiple modulated signals of        multiple streams, terminal #p does not support the reception of        such signals.    -   Also, assume that in the case of the single-carrier scheme of        “communication scheme #A”, when the other end of communication        transmits a modulated signal of a single stream, terminal #p        supports the reception of such a signal. The reception of the        multi-carrier scheme such as OFDM is not supported.    -   Additionally, in the case in which the other end of        communication performs phase change when transmitting modulated        signals of multiple streams, terminal #p supports the reception        of such signals.    -   As the error-correcting coding scheme, the decoding of        “error-correcting coding scheme #C” and the decoding of        “error-correcting coding scheme #D” are supported.

Thus, terminal #p having the configuration of FIG. 19 supporting theabove generates the reception capability notification symbols 2702illustrated in FIG. 30 on the basis of the rules described in Embodiment3, and transmits the reception capability notification symbols 2702 byfollowing the procedure in FIG. 27, for example.

At this time, terminal #p generates the reception capabilitynotification symbols 2702 illustrated in FIG. 30 with the transmissionapparatus 3403 in FIG. 34, for example, and following the procedure inFIG. 27, the transmission apparatus 3403 of FIG. 34 transmits thereception capability notification symbols 2702 illustrated in FIG. 30.

The signal processor 155 of the base station (AP) in FIG. 22 acquires abaseband signal group 154 including the reception capabilitynotification symbols 2702 transmitted by terminal #p through thereception antenna group 151 and the radio section group 153.Additionally, the signal processor 155 of the base station (AP) in FIG.22 extracts the data included in the reception capability notificationsymbols 2702, and learns that terminal #p supports the “communicationscheme #A” and the “communication scheme #B” from the data 3001 relatedto “supported schemes”.

Also, from the data 2901 related to “reception for multiple streamssupported/unsupported” in FIG. 30, the signal processor 155 of the basestation learns that “in the case of the single-carrier scheme of“communication scheme #B”, if the base station transmits multiplemodulated signals of multiple streams, terminal #p supports thereception of such signals”. Also, from the data 2901 related to“reception for multiple streams supported/unsupported” in FIG. 30, thesignal processor 155 of the base station learns that “in the case of themulti-carrier scheme such as OFDM of “communication scheme #B”, if thebase station transmits multiple modulated signals of multiple streams,terminal #p does not support the reception of such signals”. Also, fromthe data 2901 related to “reception for multiple streamssupported/unsupported” in FIG. 30, the signal processor 155 of the basestation learns that “in “communication scheme #A” and “communicationscheme #B”, if the base station transmits a modulated signal of a singlestream, terminal #p supports the reception of such a signal”.

At this time, the data 2901 related to “reception for multiple streamssupported/unsupported” needs a configuration of data like the onedescribed below, for example.

Assume that the data 2901 related to “reception for multiple streamssupported/unsupported” is made up of 2 bits, and the 2 bits areexpressed as h0 and h1.

In the case in which terminal #p supports the demodulation of multiplemodulated signals of multiple streams transmitted by the other end ofcommunication in the single-carrier scheme of “communication scheme #B”,terminal #p sets h0=1, whereas when terminal #p does not support suchdemodulation, terminal #p sets h0=0.

In the case in which terminal #p supports the demodulation of multiplemodulated signals of multiple streams transmitted by the other end ofcommunication in the multi-carrier scheme such as OFDM of “communicationscheme #B”, terminal #p sets h1=1, whereas when terminal #p does notsupport such demodulation, terminal #p sets h1=0.

Additionally, from the data 2801 related to “demodulation of modulatedsignal with phase change supported/unsupported” in FIG. 30, the signalprocessor 155 of the base station learns that terminal #p “supportsdemodulation of modulated signal with phase change”.

From the data 3002 related to “multi-carrier schemesupported/unsupported” in FIG. 30, the signal processor 155 of the basestation learns that terminal #p “supports the single-carrier schemeonly”.

From the data 3003 related to “supported error-correcting codingschemes” in FIG. 30, the signal processor 155 of the base station learnsthat terminal #p supports the decoding of “error-correcting codingscheme #C” and “error-correcting coding scheme #D”.

Consequently, by having the base station (AP) take into account thecommunication schemes supported by terminal #p, the communicationenvironment, and the like, and by having the base station (AP)appropriately generate and transmit modulated signals receivable byterminal #p, an advantageous effect of improving the data transmissionefficiency in the system including the base station (AP) and theterminal #p may be obtained.

Ninth Example

As the ninth example, suppose that the configuration of the receptionapparatus of terminal #p is the configuration illustrated in FIG. 19,and the reception apparatus of terminal #p supports the following, forexample.

-   -   The reception, for example, of “communication scheme #A” and        “communication scheme #B” described in Embodiment 3 is        supported.    -   If the other end of communication transmits multiple modulated        signals of multiple streams in “communication scheme #B”,        terminal #p supports the reception of such signals. Also, in        “communication scheme #A” and “communication scheme #B”, if the        other end of communication transmits a modulated signal of a        single stream, terminal #p supports the reception of such a        signal.    -   In the “communication scheme #B”, the base station (AP) on the        other end of communication is able to transmit multiple        modulated signals for multiple streams in the case of the        single-carrier scheme and the multi-carrier scheme such as OFDM.        However, assume that the other end of communication is able to        perform phase change when transmitting multiple modulated        signals of multiple streams only in the case of the        multi-carrier scheme such as OFDM of “communication scheme #B”.        Additionally, in the case in which the other end of        communication performs phase change when transmitting multiple        modulated signals of multiple streams, terminal #p supports the        reception of such signals.    -   As the error-correcting scheme, the decoding of        “error-correcting coding scheme #C” and the decoding of        “error-correcting coding scheme #D” are supported.

Thus, terminal #p having the configuration of FIG. 19 supporting theabove generates the reception capability notification symbols 2702illustrated in FIG. 30 on the basis of the rules described in Embodiment3, and transmits the reception capability notification symbols 2702 byfollowing the procedure in FIG. 27, for example.

At this time, terminal #p generates the reception capabilitynotification symbols 2702 illustrated in FIG. 30 with the transmissionapparatus 3403 in FIG. 34, for example, and following the procedure inFIG. 27, the transmission apparatus 3403 of FIG. 34 transmits thereception capability notification symbols 2702 illustrated in FIG. 30.

The signal processor 155 of the base station (AP) in FIG. 22 acquires abaseband signal group 154 including the reception capabilitynotification symbols 2702 transmitted by terminal #p through thereception antenna group 151 and the radio section group 153.Additionally, the signal processor 155 of the base station in FIG. 22extracts the data included in the reception capability notificationsymbols 2702, and learns that terminal #p supports the “communicationscheme #A” and the “communication scheme #B” from the data 3001 relatedto “supported schemes”.

From the data 2901 related to “reception for multiple streamssupported/unsupported” in FIG. 30, the signal processor 155 of the basestation learns that “if the other end of communication transmitsmultiple modulated signals of multiple streams with terminal #p in“communication scheme #B”, the reception of such signals is supported”.Also, from the data 2901 related to “reception for multiple streamssupported/unsupported” in FIG. 30, the signal processor 155 of the basestation learns that “if the other end of communication transmits amodulated signal of a single stream in “communication scheme #A” and“communication scheme #B”, the reception of such a signal is supported”.

Additionally, from the data 3002 related to “multi-carrier schemesupported/unsupported” in FIG. 30, the signal processor 155 of the basestation learns whether terminal #p supports the “single-carrier scheme”,supports the “multi-carrier scheme such as OFDM”, or supports “both thesingle-carrier scheme and the multi-carrier scheme such as OFDM”.

When the signal processor 155 of the base station learns that terminal#p “supports the single-carrier scheme”, the signal processor 155 of thebase station interprets the data 2801 related to “demodulation ofmodulated signal with phase change supported/unsupported” in FIG. 30 asbeing invalid, and interprets that “phase change demodulation isunsupported”. This is because the base station on the other side ofcommunication does not support phase change in the case of thesingle-carrier scheme.

When the signal processor 155 of the base station learns that terminal#p “supports the multi-carrier scheme such as OFDM” or “supports boththe single-carrier scheme and the multi-carrier scheme such as OFDM”,the signal processor 155 of the base station does not interpret the data2801 related to “demodulation of modulated signal with phase changesupported/unsupported” in FIG. 30 as being invalid (that is, interpretsthe data as being valid). From the data 2801 related to “demodulation ofmodulated signal with phase change supported/unsupported” in FIG. 30,the signal processor 155 of the base station obtains information aboutwhether terminal #p supports or does not support demodulation ofmodulated signal with phase change in the case of the multi-carrierscheme such as OFDM.

From the data 3003 related to “supported error-correcting codingschemes” in FIG. 30, the signal processor 155 of the base station learnsthat terminal #p “supports the decoding of ‘error-correcting codingscheme #C’ and the decoding of ‘error-correcting coding scheme #D’”.

Consequently, by having the base station (AP) take into account thecommunication schemes supported by terminal #p, the communicationenvironment, and the like, and by having the base station (AP)appropriately generate and transmit modulated signals receivable byterminal #p, an advantageous effect of improving the data transmissionefficiency in the system including the base station (AP) and theterminal #p may be obtained.

Tenth Example

As the tenth example, suppose that the configuration of the receptionapparatus of terminal #p is the configuration illustrated in FIG. 19,and the reception apparatus of terminal #p supports the following, forexample.

-   -   The reception, for example, of “communication scheme #A” and        “communication scheme #B” described in Embodiment 3 is        supported.    -   If the other end of communication transmits multiple modulated        signals of multiple streams in “communication scheme #B”,        terminal #p supports the reception of such signals. Also, in        “communication scheme #A” and “communication scheme #B”, if the        other end of communication transmits a modulated signal of a        single stream, terminal #p supports the reception of such a        signal.    -   In the “communication scheme #B”, the base station or AP is able        to transmit multiple modulated signals for multiple streams in        the case of the single-carrier scheme and the multi-carrier        scheme such as OFDM.    -   Additionally, in the case of the single-carrier scheme, when the        other end of communication transmits modulated signals of        multiple streams, whether or not to perform phase change may be        set, and also, in the case of the multi-carrier scheme such as        OFDM, when the other end of communication transmits modulated        signals of multiple streams, whether or not to perform phase        change may be set.    -   As the error-correcting scheme, the decoding of        “error-correcting coding scheme #C” and the decoding of        “error-correcting coding scheme #D” are supported.

Thus, terminal #p having the configuration of FIG. 19 supporting theabove generates the reception capability notification symbols 2702illustrated in FIG. 30 on the basis of the rules described in Embodiment3, and transmits the reception capability notification symbols 2702 byfollowing the procedure in FIG. 27, for example.

At this time, terminal #p generates the reception capabilitynotification symbols 2702 illustrated in FIG. 30 with the transmissionapparatus 3403 in FIG. 34, for example, and following the procedure inFIG. 27, the transmission apparatus 3403 of FIG. 34 transmits thereception capability notification symbols 2702 illustrated in FIG. 30.

The signal processor 155 of the base station (AP) in FIG. 22 acquires abaseband signal group 154 including the reception capabilitynotification symbols 2702 transmitted by terminal #p through thereception antenna group 151 and the radio section group 153.Additionally, the signal processor 155 of the base station (AP) in FIG.22 extracts the data included in the reception capability notificationsymbols 2702, and learns that terminal #p supports the “communicationscheme #A” and the “communication scheme #B” from the data 3001 relatedto “supported schemes”.

From the data 2901 related to “reception for multiple streamssupported/unsupported” in FIG. 30, the signal processor 155 of the basestation learns that “if the other end of communication transmitsmultiple modulated signals of multiple streams with terminal #p in“communication scheme #B”, the reception of such signals is supported”.Also, from the data 2901 related to “reception for multiple streamssupported/unsupported” in FIG. 30, the signal processor 155 of the basestation learns that “if the other end of communication transmits amodulated signal of a single stream in “communication scheme #A” and“communication scheme #B”, the reception of such a signal is supported”.

Additionally, from the data 3002 related to “multi-carrier schemesupported/unsupported” in FIG. 30, the signal processor 155 of the basestation learns whether terminal #p supports the “single-carrier scheme”,supports the “multi-carrier scheme such as OFDM”, or supports “both thesingle-carrier scheme and the multi-carrier scheme such as OFDM”.

Additionally, from the data 2801 related to “demodulation of modulatedsignal with phase change supported/unsupported” in FIG. 30, the signalprocessor 155 of the base station learns the conditions of phase changesupport in the terminal #p.

At this time, the data 2801 related to “demodulation of modulated signalwith phase change supported/unsupported” needs a configuration like theone described below, for example.

Assume that the data 2801 related to “demodulation of modulated signalwith phase change supported/unsupported” is made up of 2 bits, and the 2bits are expressed as k0 and k1.

In the case in which the other end of communication transmits multiplemodulated signals of multiple streams in the single-carrier scheme of“communication scheme #B”, executes phase change at that time, andterminal #p supports the demodulation of such signals, terminal #p setsk0=1, whereas when terminal #p does not support such demodulation,terminal #p sets k0=0.

In the case in which the other end of communication transmits multiplemodulated signals of multiple streams in the multi-carrier scheme suchas OFDM of “communication scheme #B”, executes phase change at thattime, and terminal #p supports the demodulation of such signals,terminal #p sets k1=1, whereas when terminal #p does not support suchdemodulation, terminal #p sets k1=0.

From the data 3003 related to “supported error-correcting codingschemes” in FIG. 30, the signal processor 155 of the base station learnsthat terminal #p supports the decoding of “error-correcting codingscheme #C” and “error-correcting coding scheme #D”.

Consequently, by having the base station (AP) take into account thecommunication schemes supported by terminal #p, the communicationenvironment, and the like, and by having the base station (AP)appropriately generate and transmit modulated signals receivable byterminal #p, an advantageous effect of improving the data transmissionefficiency in the system including the base station (AP) and theterminal #p may be obtained.

As above, the base station (AP) acquires information related to thedemodulation schemes supported by terminal #p from terminal #p on theother end of communication, and on the basis of the information, decidesthe number of modulated signals, the modulated signal communicationmethod, the signal processing method of the modulated signal, and thelike, and thereby is able to appropriately generate and transmitmodulated signals receivable by terminal #p. With this arrangement, anadvantageous effect of improved data transmission efficiency in thesystem including the base station (AP) and terminal #p may be obtained.

At this time, by including multiple pieces of data in the receptioncapability notification symbols like in FIG. 30, for example, the basestation (AP) is able to determine the validity/invalidity of the dataincluded in the reception capability notification symbols easily. Thisarrangement has an advantage of enabling fast determination of themodulated signal scheme, signal processing method, and the like fortransmission.

Additionally, on the basis of the content of the information of thereception capability notification symbols transmitted by each terminal#p, the base station (AP) is able to transmit modulated signals to eachterminal #p by a favorable transmission method, thereby improving thedata transmission efficiency.

Note that the method of configuring the data of the reception capabilitynotification symbols described in the present embodiment is an example,and the method of configuring the data of the reception capabilitynotification symbols is not limited thereto. Also, the transmissionprocedure by which terminal #p transmits the reception capabilitynotification symbols to the base station (AP) and the description of thepresent embodiment regarding the transmission timings are merely oneexample, and the configuration is not limited thereto.

Also, each terminal transmits the reception capability notificationsymbols as described above. However, depending on the terminal, thereception capability notification symbols may also not be transmitted insome cases. Subsequently, the base station (AP) receives the receptioncapability notification symbols transmitted by each terminal, andcreates the modulated signals to transmit to each terminal. Inparticular, by having the base station (AP) described in thisspecification transmit modulated signals to each terminal at identicalfrequencies (or using a subset of frequencies shared in common) andidentical times (or using a subset of times shared in common), anadvantageous effect of improved data transmission efficiency in thesystem including the base station (AP) and the terminals may be obtainedthereby.

Embodiment 6

In embodiments such as Embodiment 1, Embodiment 2, and Embodiment 3,examples of the configuration of the signal processor 206 in FIG. 2 aredescribed. In the following, an example of the configuration of thesignal processor 206 in FIG. 2 different from FIGS. 3, 4, and 26 will bedescribed. FIG. 38 is a diagram illustrating yet another example of theconfiguration of the signal processor 206 in FIG. 2. Note that in FIG.38, parts which operate similarly to FIG. 3 are denoted with the samenumbers, and a description is omitted.

A phase changer 3801B accepts the user #p mapped signal 301B expressedas sp2(t) and the control signal 300 as input. On the basis of thecontrol signal 300, the phase changer 3801B changes the phase of theuser #p mapped signal 301B, and outputs a phase-changed signal 3802B tothe weight combiner 303.

When the weighted and combined signal 304A (for user #p) output from theweight combiner 303 is expressed as zp1(i), and the weighted andcombined signal 304B (for user #p) output from the weight combiner 303is expressed as zp2(i), zp1(i) and zp2(i) are expressed by the followingFormula (43).

$\begin{matrix}\begin{matrix}{\begin{pmatrix}{{zp}\; 1(i)} \\{{zp}\; 2(i)}\end{pmatrix} = {\begin{pmatrix}a & b \\c & d\end{pmatrix}\begin{pmatrix}1 & 0 \\0 & {{vp}(i)}\end{pmatrix}\begin{pmatrix}{{sp}\; 1(i)} \\{sp2(i)}\end{pmatrix}}} \\{= {\begin{pmatrix}a & b \\c & d\end{pmatrix}\begin{pmatrix}1 & 0 \\0 & e^{j \times {{\delta p}{(i)}}}\end{pmatrix}\begin{pmatrix}{{sp}\; 1(i)} \\{{sp}\; 2(i)}\end{pmatrix}}}\end{matrix} & (43)\end{matrix}$Note that a, b, c, and d are defined as complex numbers. Consequently,the above may also be real numbers. Also, i is taken to be the symbolnumber. Note that j is the imaginary unit, and δp(i) is a real number.Additionally, zp1(i) and zp2(i) are transmitted from the transmissionapparatus at identical times and identical frequencies (identicalfrequency bands).

For example, a phase change value vp(i) in the phase changer 3801B isset like in the following Formula (44).

$\begin{matrix}{{{vp}(i)} = e^{j\frac{2 \times \pi \times i}{Np}}} & (44)\end{matrix}$In Formula (44), j is the imaginary unit. Also, Np is an integer equalto 2 or greater, and indicates the period of the phase change. If Np isset to an odd number equal to 3 or greater, there is a possibility thatthe received signal quality of the data will improve. Also, Nppreferably is set to be greater than 2, the number of streams (number ofmodulated signals) to transmit to user #p. However, Formula (44) ismerely one example, and the value of the phase change set in the phasechanger 3801B is not limited thereto.

Next, a configuration different from FIGS. 3, 4, 26, and 38 will bedescribed. FIG. 39 is a diagram illustrating yet another example of theconfiguration of the signal processor 206 in FIG. 2. Note that in FIG.39, parts which operate similarly to FIGS. 3 and 38 are denoted with thesame numbers, and a description is omitted.

A phase changer 3801A accepts the user #p mapped signal 301A expressedas sp1(t) and the control signal 300 as input. On the basis of thecontrol signal 300, the phase changer 3801A changes the phase of theuser #p mapped signal 301A, and outputs a phase-changed signal 3802A.

When the weighted and combined signal 304A (for user #p) output from theweight combiner 303 is expressed as zp1(i), and the weighted andcombined signal 304B (for user #p) output from the weight combiner 303is expressed as zp2(i), zp1(i) and zp2(i) are expressed by the followingFormula (45).

$\begin{matrix}{\begin{pmatrix}{{zp}\; 1(i)} \\{{zp}\; 2(i)}\end{pmatrix} = {{\begin{pmatrix}a & b \\c & d\end{pmatrix}\begin{pmatrix}{{Vp}(i)} & 0 \\0 & {{vp}(i)}\end{pmatrix}\begin{pmatrix}{{sp}\; 1(i)} \\{{sp}\; 2(i)}\end{pmatrix}} = {\begin{pmatrix}a & b \\c & d\end{pmatrix}\begin{pmatrix}e^{j \times \lambda\;{p{(i)}}} & 0 \\0 & e^{{jx}\;\delta\;{p{(j)}}}\end{pmatrix}\begin{pmatrix}{{sp}\; 1(i)} \\{{sp}\; 2(i)}\end{pmatrix}}}} & (45)\end{matrix}$Note that a, b, c, and d are defined as complex numbers. Consequently,the above may also be real numbers. Also, i is taken to be the symbolnumber. Note that j is the imaginary unit, and λp(i) is a real number.Additionally, zp1(i) and zp2(i) are transmitted from the transmissionapparatus at identical times (or using a subset of times shared incommon) and identical frequencies (identical frequency bands) (or usinga subset of frequencies shared in common).

By carrying out a configuration as above, particularly in an environmentin which direct waves are dominant, the base station transmits modulatedsignals using the transmission method described above, thereby enablingthe terminal on the other end of communication to obtain an advantageouseffect of acquiring high data reception quality.

Embodiment 7

In the present embodiment, the arrangement of the phase changer will bedescribed. In FIGS. 3 and 26 described above, a configuration in which aphase changer is disposed on the output side of the weight combiner 303(hereinafter also referred to as downstream of the weight combiner 303where appropriate) is illustrated. Also, in FIGS. 38 and 39, aconfiguration in which one or more phase changers are disposed on theinput side of the weight combiner 303 (hereinafter also referred to asupstream of the weight combiner 303 where appropriate) is illustrated.Phase changers may also be disposed both upstream and downstream of theweight combiner 303. In the present embodiment, an example in whichphase changers are disposed upstream and downstream of the weightcombiner 303 will be described.

FIG. 40 is a diagram illustrating a first example of disposing phasechangers upstream and downstream of the weight combiner 303. In FIG. 40,components similar to FIGS. 3, 26, 38, and 39 are denoted with the samenumbers, and a description is omitted.

As illustrated in FIG. 40, the phase changer 3801A is disposed upstreamof the weight combiner 303, on the side where the user #p mapped signal301A of sp1(t) is input (that is, the upper part of the page). The phasechanger 3801B is disposed upstream of the weight combiner 303, on theside where the user #p mapped signal 301B of sp2(t) is input (that is,the lower part). The phase changer 305A is disposed downstream of theweight combiner 303, on the side where the user #p weighted signal 304Ais output (that is, the upper part). The phase changer 305B is disposeddownstream of the weight combiner 303, on the side where the user #pweighted signal 304B is output (that is, the lower part).

As illustrated in FIG. 40, the phase changer 3801A accepts the user #pmapped signal 301A of sp1(t) and the control signal 300 as input. On thebasis of information about the phase change method included in thecontrol signal 300, for example, the phase changer 3801A changes thephase of the user #p mapped signal 301A, and outputs the phase-changedsignal 3802A.

Similarly, the phase changer 3801B accepts the user #p mapped signal301B of sp2(t) and the control signal 300 as input. On the basis ofinformation about the phase change method included in the control signal300, for example, the phase changer 3801B changes the phase of the user#p mapped signal 301B, and outputs the phase-changed signal 3802B.

Subsequently, the phase-changed signal 306A is input into the inserter307A illustrated in FIGS. 3, 26, 38, and 39, while in addition, thephase-changed signal 306B is input into the inserter 307B illustrated inFIGS. 3, 26, 38, and 39.

FIG. 41 is a diagram illustrating a second example of disposing phasechangers upstream and downstream of the weight combiner 303. In FIG. 41,components similar to FIGS. 3, 26, 38, 39, and 40 are denoted with thesame numbers, and a description is omitted.

In FIG. 41, unlike FIG. 40, only the phase changer 305B is disposeddownstream of the weight combiner 303. Subsequently, the weighted signal304A is input into the inserter 307A illustrated in FIGS. 3, 26, 38, and39. Also, the phase-changed signal 306B is input into the inserter 307Billustrated in FIGS. 3, 26, 38, and 39.

FIG. 42 is a diagram illustrating a third example of disposing phasechangers upstream and downstream of the weight combiner 303. In FIG. 42,components similar to FIGS. 3, 26, 38, 39, and 40 are denoted with thesame numbers, and a description is omitted.

In FIG. 42, unlike FIG. 41, the phase changer 305A exists on the upperpart downstream of the weight combiner 303. Subsequently, thephase-changed signal 306A is input into the inserter 307A illustrated inFIGS. 3, 26, 38, and 39. Also, the weighted signal 304B is input intothe inserter 307B illustrated in FIGS. 3, 26, 38, and 39.

FIG. 43 is a diagram illustrating a fourth example of disposing phasechangers upstream and downstream of the weight combiner 303. In FIG. 43,components similar to FIGS. 3, 26, 38, 39, and 40 are denoted with thesame numbers, and a description is omitted.

In FIG. 43, unlike FIG. 40, only the phase changer 3801B exists upstreamof the weight combiner 303. Subsequently, the phase-changed signal 306Ais input into the inserter 307A illustrated in FIGS. 3, 26, 38, and 39.Also, the phase-changed signal 306B is input into the inserter 307Billustrated in FIGS. 3, 26, 38, and 39.

FIG. 44 is a diagram illustrating a fifth example of disposing phasechangers upstream and downstream of the weight combiner 303. In FIG. 44,components similar to FIGS. 3, 26, 38, 39, and 40 are denoted with thesame numbers, and a description is omitted.

In FIG. 44, unlike FIG. 43, the phase changer 3801A exists on the upperpart upstream of the weight combiner 303. Subsequently, thephase-changed signal 306A is input into the inserter 307A illustrated inFIGS. 3, 26, 38, and 39. Also, the phase-changed signal 306B is inputinto the inserter 307B illustrated in FIGS. 3, 26, 38, and 39.

FIG. 45 is a diagram illustrating a sixth example of disposing phasechangers upstream and downstream of the weight combiner 303. In FIG. 45,components similar to FIGS. 3, 26, 38, 39, and 40 are denoted with thesame numbers, and a description is omitted.

In FIG. 45, the phase changer 3801B is disposed on the lower partupstream of the weight combiner 303, and the phase changer 305B isdisposed on the lower part downstream of the weight combiner 303.Subsequently, the weighted signal 304A is input into the inserter 307Aillustrated in FIGS. 3, 26, 38, and 39. Also, the phase-changed signal306B is input into the inserter 307B illustrated in FIGS. 3, 26, 38, and39.

FIG. 46 is a diagram illustrating a seventh example of disposing phasechangers upstream and downstream of the weight combiner 303. In FIG. 46,components similar to FIGS. 3, 26, 38, 39, and 40 are denoted with thesame numbers, and a description is omitted.

In FIG. 46, the phase changer 3801B is disposed on the lower partupstream of the weight combiner 303, and the phase changer 305A isdisposed on the upper part downstream of the weight combiner 303.Subsequently, the phase-changed signal 306A is input into the inserter307A illustrated in FIGS. 3, 26, 38, and 39. Also, the weighted signal304B is input into the inserter 307B illustrated in FIGS. 3, 26, 38, and39.

FIG. 47 is a diagram illustrating an eighth example of disposing phasechangers upstream and downstream of the weight combiner 303. In FIG. 47,components similar to FIGS. 3, 26, 38, 39, and 40 are denoted with thesame numbers, and a description is omitted.

In FIG. 47, the phase changer 3801A is disposed on the upper partupstream of the weight combiner 303, and the phase changer 305B isdisposed on the lower part downstream of the weight combiner 303.Subsequently, the weighted signal 304A is input into the inserter 307Aillustrated in FIGS. 3, 26, 38, and 39. Also, the phase-changed signal306B is input into the inserter 307B illustrated in FIGS. 3, 26, 38, and39.

FIG. 48 is a diagram illustrating a ninth example of disposing phasechangers upstream and downstream of the weight combiner 303. In FIG. 48,components similar to FIGS. 3, 26, 38, 39, and 40 are denoted with thesame numbers, and a description is omitted.

In FIG. 48, the phase changer 3801A is disposed on the upper partupstream of the weight combiner 303, and the phase changer 305A isdisposed on the upper part downstream of the weight combiner 303.Subsequently, the phase-changed signal 306A is input into the inserter307A illustrated in FIGS. 3, 26, 38, and 39. Also, the weighted signal304B is input into the inserter 307B illustrated in FIGS. 3, 26, 38, and39.

Even with configurations like the above, it is possible to carry outeach embodiment in this specification, making it possible to obtain theadvantageous effects described in each embodiment. Additionally, eachphase change method of the phase changers 3801A, 3801B, 305A, and 305Bin FIGS. 40, 41, 42, 43, 44, 45, 46, 47, and 48 is set by the controlsignal 300, for example.

Embodiment 8

In this specification, the exemplary configuration illustrated in FIG. 2is described as an example of the configuration of the user #p signalprocessor 102_p in FIG. 1. In the present embodiment, a configurationdifferent from FIG. 2 will be described as the configuration of the user#p signal processor 102_p in FIG. 1.

FIG. 49 is a diagram illustrating a different example from FIG. 2 of theconfiguration of the user #p signal processor. In FIG. 47, parts of theconfiguration which are similar to FIG. 2 are denoted with the samenumbers, and description is omitted. In FIG. 49, the point that differsfrom FIG. 2 is the existence of multiple error-correcting coders andmappers.

Specifically, in FIG. 49, two error-correcting coders (error-correctingcoders 202_1 and 202_2) exist. Note that in FIG. 2, a configurationincluding one error-correcting coder 202 is illustrated, while in FIG.49, a configuration including two error-correcting coders (202_1, 202_2)is illustrated, but the number of error-correcting coders is not limitedthereto. For example, in the case of three or more, the mapper ormappers 204 (204_1, 204_2) execute mapping using the data output by eacherror-correcting coder.

In FIG. 49, the error-correcting coder 202_1 accepts first data 201_1and the control signal 200 as input. The error-correcting coder 202_1,on the basis of information about the error-correcting coding methodincluded in the control signal 200, executes error-correcting coding onthe first data 201_1, and outputs coded data 203_1.

The mapper 204_1 accepts the coded data 203_1 and the control signal 200as input. The mapper 204_1, on the basis of information about themodulation scheme included in the control signal 200, executes mappingon the coded data 203_1, and outputs a mapped signal 205_1.

The error-correcting coder 202_2 accepts second data 201_2 and thecontrol signal 200 as input. The error-correcting coder 202_2, on thebasis of information about the error-correcting coding method includedin the control signal 200, executes error-correcting coding on thesecond data 201_2, and outputs coded data 203_2.

The mapper 204_2 accepts the coded data 203_2 and the control signal 200as input. The mapper 204_2, on the basis of information about themodulation scheme included in the control signal 200, executes mappingon the coded data 203_2, and outputs a mapped signal 205_2.

Additionally, it is possible to carry out each embodiment described inthis specification by similarly replacing the configuration illustratedin FIG. 2 as the user #p signal processor 102_p with the configurationillustrated in FIG. 49, and it is possible to obtain similaradvantageous effects.

Note that, for example, as for the user #p signal processor 102_p, it ispossible to switch between the case of generating a signal with aconfiguration like in FIG. 2 and the case of generating a signal with aconfiguration like in FIG. 49.

(Supplement 2)

In this specification, in FIGS. 3, 26, 38, 39, 40 to 48, and the likerelated to the signal processor 206 of FIG. 2, phase change is describedas being executed in the phase changer 305A and/or the phase changer305B. At this time, in the case in which NA is the period of phasechange in the phase changer 305A, provided that NA is an integer equalto 3 or greater, that is, an integer larger than the number oftransmitted streams or the number of transmitted modulated signals (2),there is a high probability that the reception apparatus on the otherend of communication will obtain favorable data reception quality.Similarly, in the case in which NB is the period of phase change in thephase changer 305B, provided that NB is an integer equal to 3 orgreater, that is, an integer larger than the number of transmittedstreams or the number of transmitted modulated signals (2), there is ahigh probability that the reception apparatus on the other end ofcommunication will obtain favorable data reception quality.

In this specification, in FIGS. 3, 26, 38, 39, 40 to 48, and the likerelated to the signal processor 206 in FIG. 2, 49, or the like, in thecase in which the weight combining (precoding) process is executed byusing only the (precoding) matrix Fp of Formula (33) or Formula (34),the signal processor 206 of FIG. 2, 49, or the like may also not beprovided with the weight combiner 303.

In this specification, in FIGS. 3, 26, 38, 39, 40 to 48, and the likerelated to the signal processor 206 of FIG. 2, phase change is describedmainly as being executed in the phase changer 305A, and/or the phasechanger 305B, and/or the phase changer 3801A, and/or the phase changer3801B. However, switching between carrying out phase change and notcarrying out phase change may also be controlled by the control signal300 input into the phase changer 305A, the phase changer 305B, the phasechanger 3801A, and the phase changer 3801B. Consequently, for example,the control signal 300 may also include control information related to“carrying out phase change or not carrying out phase change in the phasechanger 305A”, control information related to “carrying out phase changeor not carrying out phase change in the phase changer 305B”, controlinformation related to “carrying out phase change or not carrying outphase change in the phase changer 3801A”, and control informationrelated to “carrying out phase change or not carrying out phase changein the phase changer 3801B”. Also, by this control information,“carrying out phase change or not carrying out phase change in the phasechanger 305A, the phase changer 305B, the phase changer 3801A, and thephase changer 3801B” may also be controlled.

For example, the phase changer 3801A accepts the control signal 300 asinput, and in the case of receiving an instruction not to carry outphase change by the control signal 300, the phase changer 3801A outputsthe input signal 301A as 3802A. Also, the phase changer 3801B acceptsthe control signal 300 as input, and in the case of receiving aninstruction not to carry out phase change by the control signal 300, thephase changer 3801B outputs the input signal 301B as 3802B. The phasechanger 305A accepts the control signal 300 as input, and in the case ofreceiving an instruction not to carry out phase change by the controlsignal 300, the phase changer 305A outputs the input signal 304A as306A. The phase changer 305B accepts the control signal 300 as input,and in the case of receiving an instruction not to carry out phasechange by the control signal 300, the phase changer 305B outputs theinput signal 304B as 306B.

In this specification, in FIGS. 3, 26, 38, 39, and the like, phasechange is described mainly as being executed in the 309A and the phasechanger 309B. Also, the CDD (CSD) process is described mainly as beingexecuted in a CDD (CSD) section 4909A and a CDD (CSD) section 4909B.However, switching between carrying phase change or not carrying outphase change may also be controlled by the control signal 300 input intothe phase changer 309A and the phase changer 309B.

Consequently, for example, the control signal 300 may also includecontrol information related to “carrying out phase change or notcarrying out phase change in the phase changer 309A” and controlinformation related to “carrying out phase change or not carrying outphase change in the phase changer 309B”, and by this controlinformation, “carrying out phase change or not carrying out phase changein the phase changer 309A and the phase changer 308B” may also becontrolled.

Also, switching between carrying out the CDD (CSD) process or notcarrying out the CDD (CSD) process may also be controlled by the controlsignal 300 input into the CDD (CSD) section 4909A and the CDD (CSD)section 4909B. Consequently, for example, the control signal 300 mayalso include control information related to “carrying out the CDD (CSD)process or not carrying out the CDD (CSD) process in the CDD (CSD)section 4909A”, and control information related to “carrying out the CDD(CSD) process or not carrying out the CDD (CSD) process in the CDD (CSD)section 4909B”, and by this control information, “carrying out the CDD(CSD) process or not carrying out the CDD (CSD) process in the CDD (CSD)sections 4909A and 4909B” may also be controlled.

For example, the phase changer 309A accepts the control signal 300 asinput, and in the case of receiving an instruction not to carry outphase change by the control signal 300, the phase changer 309A outputsthe input signal 308A as 310A. Also, the phase changer 309B accepts thecontrol signal 300 as input, and in the case of receiving an instructionnot to carry out phase change by the control signal 300, the phasechanger 309B outputs the input signal 308B as 310B. Additionally, theCDD (CSD) section 4909A accepts the control signal 300 as input, and inthe case of receiving an instruction not to carry out the CDD (CSD)process, the CDD (CSD) section 4909A outputs the input signal 308A as4910A. Also, the CDD (CSD) section 4909B accepts the control signal 300as input, and in the case of receiving an instruction not to carry outthe CDD (CSD) process, the CDD (CSD) section 4909B outputs the inputsignal 308B as 4910B.

Note that obviously the embodiments described in this specification andother content, such as the content described in the supplements, mayalso be combined plurally.

Also, in the description in this specification, the terms “base station(or AP)” and “terminal” are used to describe each embodiment, and arenon-limiting. Consequently, in each embodiment, the operations describedas the operations of the “base station (or AP)” may also be theoperations of a “terminal”, a “communication apparatus”, a “broadcastingstation”, a “mobile phone”, a “personal computer”, a “television”, orthe like. Similarly, in each embodiment, the operations described as theoperations of the “terminal” may also be the operations of a “basestation (or AP)”, a “communication apparatus”, a “broadcasting station”,a “mobile phone”, a “personal computer”, a “television”, or the like.

Embodiment 9

In the present embodiment, phase change is described as being executedby the phase changers 305A, 305B, 3801A, and 3801B according to FIGS. 3,26, 38, 39, 40 to 48, or the like, and an example of the transmissionstate and an example of the reception state at this time will bedescribed. Additionally, as an example, the operations in FIG. 3 will bedescribed.

First, for the sake of comparison, the case in which phase change is notexecuted by the phase changer 305B in FIG. 3 will be described.

FIG. 50A is a diagram illustrating a first example of a state of signalpoints of a signal transmitted in a transmission apparatus that includesthe configuration of FIG. 3. FIG. 50B is a diagram illustrating a firstexample of a state of signal points of a signal received in a receptionapparatus on the other end of communication with a transmissionapparatus that includes FIG. 3. In FIGS. 50A and 50B, the state ofsignal points on the in-phase I-quadrature Q plane is illustratedsuccessively in the direction of the horizontal axis for each symbolnumber.

Note that the example illustrated in FIGS. 50A and 50B is an example ofthe case in which, in the transmission apparatus, the phase changer 305Bof FIG. 3 is assumed not to operate, while in the weight combiner 303,the weight combining of any of Formulas (33), (34), (35), and (36) isassumed to be executed. Also, assume that the modulation schemeperformed on sp1(i) of the mapped signal 301A is QPSK, and that themodulation scheme performed on sp2(i) of the mapped signal 301B is QPSK.

In FIG. 50A, 6800_1 illustrates the state of signal points of zp1(i) ofthe signal 304A for the symbol number #0, and ⋅ represents the signalpoints. Note that 4 signal points exist. In FIG. 50A, 6800_2 illustratesthe state of signal points of zp2(i) of the signal 306B for the symbolnumber #0, and ⋅ represents the signal points. Note that 4 signal pointsexist. In FIG. 50A, 6801_1 illustrates the state of signal points ofzp1(i) of the signal 304A for the symbol number #1, and ⋅ represents thesignal points. Note that 4 signal points exist. In FIG. 50A, 6801_2illustrates the state of signal points of zp2(i) of the signal 306B forthe symbol number #1, and ⋅ represents the signal points. Note that 4signal points exist. In FIG. 50A, 6802_1 illustrates the state of signalpoints of zp1(i) of the signal 304A for the symbol number #2, and ⋅represents the signal points. Note that 4 signal points exist. In FIG.50A, 6802_2 illustrates the state of signal points of zp2(i) of thesignal 306B for the symbol number #2, and ⋅ represents the signalpoints. Note that 4 signal points exist.

FIG. 50B is the state of signal points during reception with respect tothe state of signal points in the transmitted signal illustrated in FIG.50A. Note that to simplify the description, as an example of an LOSenvironment, assume that the channel matrix of Formula (41) is expressedby the following Formula (46).

$\begin{matrix}{\begin{pmatrix}{h11(i)} & {h12(i)} \\{h\; 21(i)} & {h22(i)}\end{pmatrix} = \begin{pmatrix}1 & 1 \\1 & 1\end{pmatrix}} & (46)\end{matrix}$

In FIG. 50B, 6810_1 indicates the state of signal points duringreception of Rx1(i), which is the received signal 1902X in FIG. 19 forthe symbol number #0, and ⋅ represents the signal points. Note that 9signal points exist. In FIG. 50B, 6810_2 indicates the state of signalpoints during reception of Rx2(i), which is the received signal 1902Y inFIG. 19 for the symbol number #0, and ⋅ represents the signal points.Note that 9 signal points exist. In FIG. 50B, 6811_1 indicates the stateof signal points during reception of Rx1(i), which is the receivedsignal 1902X in FIG. 19 for the symbol number #1, and ⋅ represents thesignal points. Note that 9 signal points exist. In FIG. 50B, 6811_2indicates the state of signal points during reception of Rx2(i), whichis the received signal 1902Y in FIG. 19 for the symbol number #1, and ⋅represents the signal points. Note that 9 signal points exist. In FIG.50B, 6812_1 indicates the state of signal points during reception ofRx1(i), which is the received signal 1902X in FIG. 19 for the symbolnumber #2, and ⋅ represents the signal points. Note that 9 signal pointsexist. In FIG. 50B, 6812_2 indicates the state of signal points duringreception of Rx2(i), which is the received signal 1902Y in FIG. 19 forthe symbol number #2, and ⋅ represents the signal points. Note that 9signal points exist.

In the case of transmitting modulated signals like in FIG. 50A, thesignal points at the reception apparatus become like FIG. 50B. In thiscase, the number of signal points during reception becomes 9, and inaddition, this state has the characteristic of not changing even if thesymbol number changes. Note that, ideally, 16 signal points would exist,but in this state, obtaining a high data reception quality at thereception apparatus is difficult.

Next, the case in which phase change is executed by the phase changer305B in FIG. 3 will be described.

FIG. 51A is a diagram illustrating a second example of a state of signalpoints of a signal transmitted in a transmission apparatus that includesthe configuration of FIG. 3. FIG. 51B is a diagram illustrating a secondexample of a state of signal points of a signal received in a receptionapparatus on the other end of communication with a transmissionapparatus that includes FIG. 3. In FIGS. 51A and 51B, the state ofsignal points on the in-phase I-quadrature Q plane is illustratedsuccessively in the direction of the horizontal axis for each symbolnumber.

Note that the example illustrated in FIGS. 51A and 51B is an example ofthe case in which, in the transmission apparatus, the phase changer 305Boperates, while in the weight combiner 303, the weight combining of anyof Formulas (33), (34), (35), and (36) is executed. Also, assume thatthe modulation scheme performed on sp1(i) of the mapped signal 301A isQPSK, and that the modulation scheme performed on sp2(i) of the mappedsignal 301B is QPSK.

In FIG. 51A, 6900_1 illustrates the state of signal points of zp1(i) ofthe signal 304A for the symbol number #0, and ⋅ represents the signalpoints. Note that 4 signal points exist. In FIG. 51A, 6900_2 illustratesthe state of signal points of zp2(i) of the signal 306B for the symbolnumber #0, and ⋅ represents the signal points. Note that 4 signal pointsexist. In FIG. 51A, 6901_1 illustrates the state of signal points ofzp1(i) of the signal 304A for the symbol number #1, and ⋅ represents thesignal points. Note that 4 signal points exist. In FIG. 51A, 6901_2illustrates the state of signal points of zp2(i) of the signal 306B forthe symbol number #1, and ⋅ represents the signal points. Note that 4signal points exist. Additionally, since the phase changer 305Boperates, and phase change is performed, the phase of the signal pointsillustrated in 6901_2 is changed from the signal points illustrated in6900_2. In FIG. 51A, 6902_1 illustrates the state of signal points ofzp1(i) of the signal 304A for the symbol number #2, and ⋅ represents thesignal points. Note that 4 signal points exist. In FIG. 51A, 6902_2illustrates the state of signal points of zp2(i) of the signal 306B forthe symbol number #2, and ⋅ represents the signal points. Note that 4signal points exist. Additionally, since the phase changer 305Boperates, and phase change is performed, the phase of the signal pointsillustrated in 6902_2 is changed from the signal points illustrated in6901_2.

FIG. 51B is the state of signal points during reception with respect tothe state of signal points in the transmitted signal illustrated in FIG.51A. Note that to simplify the description, as an example of an LOSenvironment, assume that the channel matrix is expressed by Formula(46).

In FIG. 51B, 6910_1 indicates the state of signal points duringreception of Rx1(i), which is the received signal 1902X in FIG. 19 forthe symbol number #0, and ⋅ represents the signal points. Note that 9signal points exist. In FIG. 51B, 6910_2 indicates the state of signalpoints during reception of Rx2(i), which is the received signal 1902Y inFIG. 19 for the symbol number #0, and ⋅ represents the signal points.Note that 9 signal points exist. In FIG. 51B, 6911_1 indicates the stateof signal points during reception of Rx1(i), which is the receivedsignal 1902X in FIG. 19 for the symbol number #1, and ⋅ represents thesignal points. Note that 16 signal points exist. Although the positionsand number of signal points has changed from 6910_1, as illustrated inFIG. 51A, this is because the phase of the signal points illustrated in6901_2 has been changed from the signal points illustrated in 6900_2. InFIG. 51B, 6911_2 indicates the state of signal points during receptionof Rx2(i), which is the received signal 1902Y in FIG. 19 for the symbolnumber #1, and ⋅ represents the signal points. Note that 16 signalpoints exist. Although the positions and number of signal points haschanged from 6910_2, as illustrated in FIG. 51A, this is because thephase of the signal points illustrated in 6901_2 has been changed fromthe signal points illustrated in 6900_2. In FIG. 51B, 6912_1 indicatesthe state of signal points during reception of Rx1(i), which is thereceived signal 1902X in FIG. 19 for the symbol number #2, and ⋅represents the signal points. Note that 16 signal points exist. Althoughthe positions of signal points has changed from 6911_1, as illustratedin FIG. 51A, this is because the phase of the signal points illustratedin 6902_2 has been changed from the signal points illustrated in 6901_2.In FIG. 51B, 6912_2 indicates the state of signal points duringreception of Rx2(i), which is the received signal 1902Y in FIG. 19 forthe symbol number #2, and ⋅ represents the signal points. Note that 16signal points exist. Although the positions of signal points has changedfrom 6911_2, as illustrated in FIG. 51A, this is because the phase ofthe signal points illustrated in 6902_2 has been changed from the signalpoints illustrated in 6901_2.

In the case of transmitting modulated signals like in FIG. 51A, thesignal points at the reception apparatus become like FIG. 51B, thenumber of existing signal points may be 16, and additionally, if thesymbol numbers change, the positions where the signal points exist inthe in-phase I-quadrature Q plane change.

In this way, by executing phase change in the transmission apparatus inthe case of a state in which the radio wave conditions are steady, likean LOS environment, at the reception apparatus, the state of signalpoints during reception changes, and thus there is a higher probabilityof being able to obtain an advantageous effect of improved datareception quality at the reception apparatus.

Note that the above description is merely one example, and to “inducechange in the state of reception at the reception apparatus in a steadystate like an LOS environment” as described above, for example, there isthe method of executing phase change with the phase changers 305A, 305B,3801A, and 3801B according to FIGS. 3, 26, 38, 39, 40 to 48, and thelike. Even with such a configuration, as described above, there is ahigher probability of being able to obtain an advantageous effect ofimproved data reception quality.

[Description of Operation of Reception Apparatus]

As described above, the reception apparatus illustrated in FIG. 19receives a received signal in which the signal point arrangement duringreception changes as a result of phase change being executed.Hereinafter, a supplementary description of the operation of thereception apparatus in FIG. 19 will be given. The case in which thetransmission apparatus has the configuration illustrated in FIGS. 3, 26,and the like, or in other words, the configuration in which a phasechanger is disposed downstream of the weight combiner, and thetransmission apparatus generates and transmits modulated signals will bedescribed.

For example, the transmission apparatus transmits modulated signals withthe frame configuration like (FIGS. 8 and 9) or (FIGS. 10 and 11).

In the reception apparatus of terminal #p in FIG. 19, the controlinformation decoder 1909 obtains information such as the transmissionmethod, the modulation scheme, and the error-correcting coding methodused to generate data symbols from the control information symbols in(FIGS. 8 and 9) or (FIGS. 10 and 11). Also, in the case in which thetransmission apparatus performs phase change, the control informationdecoder 1909 obtains information about “how phase change was performedon the data symbols” included in the control information symbols, and inthe demodulation of the data symbols, outputs a control signal 1901including information related to the phase change method so thatdemodulation that takes the phase change into account can be executed.Note that the control signal 1901 is also assumed to include informationabout the transmission method, the method of the modulation scheme, theerror-correcting coding method, and the like.

As described in FIG. 20, the received signals r1(i) and r2(i) areexpressed as in Formula (41). From Formulas (3), (41), and (42), thereceived signals r1(i) and r2(i) are expressed as in the followingFormula (47).

$\begin{matrix}{\begin{pmatrix}{r\; 1(i)} \\{r\; 2(i)}\end{pmatrix} = {{{\begin{pmatrix}{h\; 11(i)} & {h\; 12(i)} \\{h\; 21(i)} & {h\; 22(i)}\end{pmatrix}\begin{pmatrix}{{Yp}(i)} & 0 \\0 & {{yp}(i)}\end{pmatrix}{{Fp}\begin{pmatrix}{{sp}\; 1(i)} \\{{sp}\; 2(i)}\end{pmatrix}}} + \begin{pmatrix}{n\; 1(i)} \\{n\; 2(i)}\end{pmatrix}} = {{\begin{pmatrix}{h\; 11(i)} & {h\; 12(i)} \\{h\; 21(i)} & {h\; 22(i)}\end{pmatrix}\begin{pmatrix}{{Yp}(i)} & 0 \\0 & {{yp}(i)}\end{pmatrix}\begin{pmatrix}a & b \\c & d\end{pmatrix}\begin{pmatrix}{{sp}\; 1(i)} \\{{sp}\; 2(i)}\end{pmatrix}} + \begin{pmatrix}{n\; 1(i)} \\{n\; 2(i)}\end{pmatrix}}}} & (47)\end{matrix}$

Note that in the case of not executing phase change by the phase changer305A (or in the case in which the phase changer 305A does not exist),Yp(i)=1. Also, in the case of not executing phase change by the phasechanger 305B (or in the case in which the phase changer 305B does notexist), yp(i)=1.

The modulated signal u1 channel estimator 1905_1 uses the preamble andpilot symbols in (FIGS. 8 and 9) or (FIGS. 10 and 11) to estimate andoutput h11(i) of Formula (47) (see 1906_1 in FIG. 19). The modulatedsignal u2 channel estimator 1905_2 uses the preamble and pilot symbolsin (FIGS. 8 and 9) or (FIGS. 10 and 11) to estimate and output h12(i) ofFormula (47) (see 1906_2 in FIG. 19). The modulated signal u1 channelestimator 1907_1 uses the preamble and pilot symbols in (FIGS. 8 and 9)or (FIGS. 10 and 11) to estimate and output h21(i) of Formula (47) (see1908_1 in FIG. 19). The modulated signal u2 channel estimator 1907_2uses the preamble and pilot symbols in (FIGS. 8 and 9) or (FIGS. 10 and11) to estimate and output h22(i) of Formula (47) (see 1908_2 in FIG.19).

Since the relationship of Formula (47) is understood by the inputsignal, the signal processor 1911 executes demodulation of sp1(i) andsp2(i) from the relationship of Formula (47), and after that, executeserror-correcting decoding to thereby obtain and output the received data1912.

The case in which the transmission apparatus has a configuration like inFIGS. 40 to 48, or in other words, a configuration in which phasechangers are disposed both upstream and downstream of the weightcombiner, and the transmission apparatus generates and transmitsmodulated signals will be described.

For example, the transmission apparatus transmits modulated signals withthe frame configuration like (FIGS. 8 and 9) or (FIGS. 10 and 11).

In the reception apparatus of terminal #p in FIG. 19, the controlinformation decoder 1909 obtains information such as the transmissionmethod, the modulation scheme, and the error-correcting coding methodused to generate data symbols from the control information symbols in(FIGS. 8 and 9) or (FIGS. 10 and 11). Also, in the case in which thetransmission apparatus performs phase change, the control informationdecoder 1909 obtains information about “how phase change was performedon the data symbols” included in the control information symbols, and inthe demodulation of the data symbols, outputs a control signal 1901including information related to the phase change method so thatdemodulation that takes the phase change into account can be executed.Note that the control signal 1901 is also assumed to include informationabout the transmission method, the method of the modulation scheme, theerror-correcting coding method, and the like.

As described in FIG. 20, the received signals r1(i) and r2(i) areexpressed as in Formula (41). At this time, from Formulas (3), (41),(42), and (45), the received signals r1(i) and r2(i) are expressed as inthe following Formula (48).

$\begin{matrix}{\begin{pmatrix}{r\; 1(i)} \\{r\; 2(i)}\end{pmatrix} = {{{\begin{pmatrix}{h\; 11(i)} & {h\; 12(i)} \\{h\; 21(i)} & {h\; 22(i)}\end{pmatrix}\begin{pmatrix}{{Yp}(i)} & 0 \\0 & {{yp}(i)}\end{pmatrix}{{Fp}\begin{pmatrix}{{Vp}(i)} & 0 \\0 & {{vp}(i)}\end{pmatrix}}\begin{pmatrix}{{sp}\; 1(i)} \\{{sp}\; 2(i)}\end{pmatrix}} + \begin{pmatrix}{n\; 1(i)} \\{n\; 2(i)}\end{pmatrix}} = {{\begin{pmatrix}{h\; 11(i)} & {h\; 12(i)} \\{h\; 21(i)} & {h\; 22(i)}\end{pmatrix}\begin{pmatrix}{{Yp}(i)} & 0 \\0 & {{yp}(i)}\end{pmatrix}\begin{pmatrix}a & b \\c & d\end{pmatrix}\begin{pmatrix}{{Vp}(i)} & 0 \\0 & {{vp}(i)}\end{pmatrix}\begin{pmatrix}{{sp}\; 1(i)} \\{{sp}\; 2(i)}\end{pmatrix}} + \begin{pmatrix}{n\; 1(i)} \\{n\; 2(i)}\end{pmatrix}}}} & (48)\end{matrix}$

Note that in the case of not executing phase change by the phase changer305A (or in the case in which the phase changer 305A does not exist),Yp(i)=1. Also, in the case of not executing phase change by the phasechanger 305B (or in the case in which the phase changer 305B does notexist), yp(i)=1. Also, in the case of not executing phase change by thephase changer 3801A (or in the case in which the phase changer 3801Adoes not exist), Vp(i)=1. Also, in the case of not executing phasechange by the phase changer 3801B (or in the case in which the phasechanger 3801B does not exist), vp(i)=1.

The modulated signal u1 channel estimator 1905_1 uses the preamble andpilot symbols in (FIGS. 8 and 9) or (FIGS. 10 and 11) to estimate andoutput h11(i) of Formula (48) (see 1906_1 in FIG. 19). The modulatedsignal u2 channel estimator 1905_2 uses the preamble and pilot symbolsin (FIGS. 8 and 9) or (FIGS. 10 and 11) to estimate and output h12(i) ofFormula (48) (see 1906_2 in FIG. 19). The modulated signal u1 channelestimator 1907_1 uses the preamble and pilot symbols in (FIGS. 8 and 9)or (FIGS. 10 and 11) to estimate and output h21(i) of Formula (48) (see1908_1 in FIG. 19). The modulated signal u2 channel estimator 1907_2uses the preamble and pilot symbols in (FIGS. 8 and 9) or (FIGS. 10 and11) to estimate and output h22(i) of Formula (48) (see 1908_2 in FIG.19).

Since the relationship of Formula (48) is understood by the inputsignal, the signal processor 1911 executes demodulation of sp1(i) andsp2(i) from the relationship of Formula (48), and after that, executeserror-correcting decoding to thereby obtain and output the received data1912.

Embodiment 10

In the present embodiment, a configuration of a transmission apparatusof a base station, an access point, a broadcasting station, or the like,for example, which is a configuration of a transmission apparatusdifferent from FIG. 1, will be described.

FIG. 52 is a diagram illustrating a different example from FIG. 1 of theconfiguration of a transmission apparatus of a base station (AP). Notethat in FIG. 52, parts of the configuration which are similar to FIG. 1are denoted with the same numbers, and description is omitted.

The points by which FIG. 52 and FIG. 1 are different are that themultiplexing signal processor 104 in FIG. 1 is broken up into per-usermultiplexing signal processors (multiplexing signal processors 7000_1 to7000_M) in FIG. 52, and that adders (adder 7002_1 to adder 7002_N) existdownstream of the multiplexing signal processors.

The multiplexing signal processor 7000_1 accepts the control signal 100,the user #1 first baseband signal 103_1_1, the user #1 second basebandsignal 103_1_2, and the (common) reference signal 199 as input. On thebasis of the control signal 100, the multiplexing signal processor7000_1 performs multiplexing signal processing on the user #1 firstbaseband signal 103_1_1 and the user #1 second baseband signal 103_1_2,and generates and outputs a user #1 multiplexed signal $1 basebandsignal 7001_1_1 to a user #1 multiplexed signal $N baseband signal7001_1_N. Note that N is an integer equal to 1 or greater. Also, in thecase of treating q as an integer from 1 to N, a user #1 multiplexedsignal $q baseband signal 7001_1_q exists. Also, a reference signal maybe included in the user #1 multiplexed signal $1 baseband signal7001_1_1 to the user #1 multiplexed signal $N baseband signal 7001_1_N.

Similarly, the multiplexing signal processor 7000_2 accepts the controlsignal 100, the user #2 first baseband signal 103_2_1, the user #2second baseband signal 103_2_2, and the (common) reference signal 199 asinput. On the basis of the control signal 100, the multiplexing signalprocessor 7000_2 performs multiplexing signal processing on the user #2first baseband signal 103_2_1 and the user #2 second baseband signal103_2_2, and generates and outputs a user #2 multiplexed signal $1baseband signal 7001_2_1 to a user #2 multiplexed signal $N basebandsignal 7001_2_N. Note that N is an integer equal to 1 or greater. Also,in the case of treating q as an integer from 1 to N, a user #2multiplexed signal $q baseband signal 7001_2_q exists. Also, a referencesignal may be included in the user #2 multiplexed signal $1 basebandsignal 7001_2_1 to the user #2 multiplexed signal $N baseband signal7001_2_N.

Similarly, the multiplexing signal processor 7000_M accepts the controlsignal 100, the user #M first baseband signal 103_M_1, the user #Msecond baseband signal 103_M_2, and the (common) reference signal 199 asinput. On the basis of the control signal 100, the multiplexing signalprocessor 7000_M performs multiplexing signal processing on the user #Mfirst baseband signal 103_M_1 and the user #2 second baseband signal103_M_2, and generates and outputs a user #M multiplexed signal $1baseband signal 7001_M_1 to a user #M multiplexed signal $N basebandsignal 7001_M_N. Note that N is an integer equal to 1 or greater. Also,in the case of treating q as an integer from 1 to N, a user #Mmultiplexed signal $q baseband signal 7001_M_q exists. Also, a referencesignal may be included in the user #M multiplexed signal $1 basebandsignal 7001_M_1 to the user #M multiplexed signal $N baseband signal7001_M_N.

Consequently, the multiplexing signal processor 7000_p (where p is aninteger from 1 to M) accepts the control signal 100, the user #p firstbaseband signal 103_p_1, and the user #p second baseband signal 103_p_2as input. On the basis of the control signal 100, the multiplexingsignal processor 7000_p performs multiplexing signal processing on theuser #p first baseband signal 103_p_1 and the user #p second basebandsignal 103_p_2, and generates and outputs a user #p multiplexed signal$1 baseband signal 7001_p_1 to a user #p multiplexed signal $N basebandsignal 7001_p_N. Note that N is an integer equal to 1 or greater. Also,in the case of treating q as an integer from 1 to N, a user #pmultiplexed signal $q baseband signal 7001_p_q exists. Also, a referencesignal may be included in the user #p multiplexed signal $1 basebandsignal 7001_p_1 to the user #p multiplexed signal $N baseband signal7001_p_N.

The adder 7002_1 accepts the user #1 multiplexed signal $1 basebandsignal 7001_1_1 to the user #M multiplexed signal $1 baseband signal7001_M_1 as input. In other words, in the case of treating p as aninteger from 1 to M, a user #p multiplexed signal $1 baseband signal7001_p_1 is treated as input. The adder 7002_1 adds together the user #1multiplexed signal $1 baseband signal 7001_1_1 to the user #Mmultiplexed signal $1 baseband signal 7001_M_1, and outputs a firstadded signal 7003_1.

Similarly, the adder 7002_2 accepts the user #1 multiplexed signal $2baseband signal 7001_1_2 to the user #M multiplexed signal $2 basebandsignal 7001_M_2 as input. In other words, in the case of treating p asan integer from 1 to M, a user #p multiplexed signal $2 baseband signal7001_p_2 is treated as input. The adder 7002_2 adds together the user #1multiplexed signal $2 baseband signal 7001_1_2 to the user #Mmultiplexed signal $2 baseband signal 7001_M_2, and outputs a secondadded signal 7003_2.

The adder 7002_N accepts the user #1 multiplexed signal $N basebandsignal 7001_1_N to the user #M multiplexed signal $N baseband signal7001_M_N as input. In other words, in the case of treating p as aninteger from 1 to M, a user #p multiplexed signal $N baseband signal7001_p_N is treated as input. The adder 7002_N adds together the user #1multiplexed signal $N baseband signal 7001_1_N to the user #Mmultiplexed signal $N baseband signal 7001_M_N, and outputs an Nth addedsignal 7003_N.

Consequently, the adder 7002_q accepts the user #1 multiplexed signal $qbaseband signal 7001_1_q to the user #M multiplexed signal $q basebandsignal 7001_M_q as input. In other words, in the case of treating p asan integer from 1 to M, a user #p multiplexed signal $q baseband signal7001_p_q is treated as input. The adder 7002_q adds together the user #1multiplexed signal $q baseband signal 7001_1_q to the user #Mmultiplexed signal $q baseband signal 7001_M_q, and outputs a qth addedsignal 7003_q. At this time, q is an integer from 1 to N.

The radio section $1 (106_1) accepts the control signal 100 and thefirst added signal 7003_1 as input, executes processes such as frequencyconversion and amplification on the first added signal 7003_1 on thebasis of the control signal 100, and outputs the transmission signal107_1.

Similarly, the radio section $2 (106_2) accepts the control signal 100and the second added signal 7003_2 as input, executes processes such asfrequency conversion and amplification on the second added signal 7003_2on the basis of the control signal 100, and outputs the transmissionsignal 107_2.

Similarly, the radio section $N (106_N) accepts the control signal 100and the Nth added signal 7003_N as input, executes processes such asfrequency conversion and amplification on the Nth added signal 7003_N onthe basis of the control signal 100, and outputs the transmission signal107_N.

Consequently, the radio section $q (106_q) accepts the control signal100 and the qth added signal 7003_q as input, executes processes such asfrequency conversion and amplification on the qth added signal 7003_q onthe basis of the control signal 100, and outputs the transmission signal107_q. At this time, q is an integer from 1 to N.

Next, an example of the operations of the multiplexing signal processor7000_p will be described.

For example, on the basis of Formula (3), Formula (42), or the like,assume that the user #p first baseband signal 103_p_1 and the user #psecond baseband signal 103_p_2 output by the user #p signal processor102_p (where p is an integer from 1 to M) in FIG. 52 are expressed aszp1(i) and zp2(i), respectively. However, zp1(i) and zp2(i) may begenerated by a process other than Formula (3) or Formula (42), and inaddition, zp1(i)=0 and zp2(i)=0 is also acceptable. Note that whenzp1(i)=0, zp1(i) does not exist, and when zp2(i)=0, zp2(i) does notexist.

If the user #p multiplexed signal $q baseband signal 7001_p_q output bythe multiplexing signal processor 7000_p is expressed as gpq(i), thengpq(i) is expressed by the following Formula (49).gpq(i)=a_p_q_1(i)×zp1(i)+a_p_q_2(i)×zp2(i)  (49)At this time, a_p_q_1(i) and a_p_q_2(i) are multiplexing weightingcoefficients, and may be defined as complex numbers. Thus, a_p_q_1(i)and a_p_q_2(i) may also be real numbers. Also, a_p_q_1(i) and a_p_q_2(i)are described as functions of the symbol number i, but the value doesnot have to change for every symbol. Additionally, a_p_q_1(i) anda_p_q_2(i) are decided on the basis of the feedback information of eachterminal.

Note that in FIG. 52, the number of baseband signals for user #p outputby the user #p signal processor 102_p is not limited to two or less. Forexample, suppose that the number of baseband signals for user #p outputby the user #p signal processor 102_p is S or less. Note that S is takento be an integer equal to 1 or greater. Additionally, suppose that theuser #p kth baseband signal (where k is an integer from 1 to S) isexpressed as zpk(i).

At this time, if the user #p multiplexed signal $q baseband signal7001_p_q output by the multiplexing signal processor 7000_p is expressedas gpq(i), then gpq(i) is expressed by the following Formula (50).

$\begin{matrix}{{{gpq}(i)} = {\sum\limits_{k = 1}^{S}{{a\_ p}{\_ q}{\_ k}(i) \times {{zpk}(i)}}}} & (50)\end{matrix}$At this time, a_p_q_k(i) is a multiplexing weighting coefficient, andmay be defined as a complex number. Thus, a_p_q_k(i) may also be a realnumber. Also, a_p_q_k(i) is described as a function of the symbol numberi, but the value does not have to change for every symbol. Additionally,a_p_q_k(i) is decided on the basis of the feedback information of eachterminal.

Next, an example of the operations of the adder 7002_q will bedescribed.

Suppose that the qth added signal 7003_q output by the adder 7002_q inFIG. 52 is expressed as eq(i). Accordingly, eq(i) is expressed by thefollowing Formula (51).

$\begin{matrix}{{{eq}(i)} = {\sum\limits_{k = 1}^{M}{{gkq}(i)}}} & (51)\end{matrix}$

As above, even if the configuration of the transmission apparatus in thebase station or AP is a configuration like the one in FIG. 52, eachembodiment described in this specification may be carried out in asimilar manner, and the advantageous effects described in eachembodiment may be obtained in a similar manner.

(Supplement 3)

In this specification, when the transmission apparatus of the basestation or AP transmits a modulated signal of a single stream, FIG. 35is illustrated as an example of the configuration of the receptionapparatus of terminal #p on the other end of communication with the basestation or AP, but the configuration of terminal #p that receives themodulated signal of a single stream is not limited to FIG. 35, and forexample, the reception apparatus of terminal #p may also have aconfiguration equipped with multiple reception antennas. For example, inFIG. 19, in the case in which the modulated signal u2 channel estimators1905_2 and 1907_2 do not operate, the channel estimators operate withrespect to a single modulated signal, and thus even with such aconfiguration, the modulated signal of a single stream may be received.

Consequently, in the description in this specification, even if theembodiment described using FIG. 35 has the reception apparatusconfiguration of the above description instead of FIG. 35, similaroperation may be achieved, and similar advantageous effects may beobtained.

Embodiment 11

In the present embodiment, a different embodiment method of theoperations of terminal #p described in Embodiment 3, Embodiment 5, andthe like will be described.

Since an example of the configuration of terminal #p has already beendescribed using FIG. 34 and the like, a description is omitted. Also,since an example of the configuration of the reception apparatus 3404 ofterminal #p in FIG. 34 has been described using FIG. 35 and the like, adescription is omitted.

Since an example of the frame configuration when transmitting amodulated signal of a single stream using the multi-carrier transmissionscheme such as OFDM by the base station or AP on the other end ofcommunication with terminal #p has been described using FIG. 36 and thelike, a description is omitted.

For example, the transmission apparatus of the base station (AP) in FIG.1 may also transmit a modulated signal of a single stream with the frameconfiguration in FIG. 36.

Since an example of the frame configuration when transmitting amodulated signal of a single stream using the single-carriertransmission scheme by the base station or AP on the other end ofcommunication with terminal #p has been described using FIG. 37 and thelike, a description is omitted.

For example, the transmission apparatus of the base station (AP) in FIG.1 may also transmit a modulated signal of a single stream with the frameconfiguration in FIG. 37.

Also, for example, the transmission apparatus of the base station (AP)in FIG. 1 may also transmit modulated signals of multiple streams withthe frame configuration in FIGS. 8 and 9.

Furthermore, for example, the transmission apparatus of the base station(AP) in FIG. 1 may also transmit modulated signals of multiple streamswith the frame configuration in FIGS. 10 and 11.

FIG. 53 is a diagram illustrating a different example from FIGS. 28, 29,and 30 of data included in the reception capability notification symbols2702 transmitted by terminal #p in FIG. 27. Note that the parts of theconfiguration which are similar to FIGS. 28, 29, and 30 are denoted withthe same numbers. Additionally, a description is omitted for parts whichoperate similarly to FIGS. 28, 29, and 30.

The example of data illustrated in FIG. 53 takes a configuration inwhich data 5301 related to “supported precoding methods” has been addedto the example of data in FIG. 30. Hereinafter, the data 5301 related to“supported precoding methods” will be described.

Assume that when transmitting multiple modulated signals for multiplestreams, the base station or AP is able to select one precoding methodfrom among multiple precoding methods, executes weight combining (forexample, by the weight combiner 303 in FIG. 3) according to the selectedprecoding method, and generates and transmits the modulated signals.Note that, as described in this specification, the base station or APmay also perform phase change.

At this time, the data by which terminal #p notifies the base station orAP “whether or not demodulation of a modulated signal is possible whenthe base station or AP performs one precoding among the multipleprecoding” becomes the data 5301 related to “supported precodingmethods”.

For example, assume that when the base station or AP generates themodulated signals of multiple streams with respect to terminal #p, thereis a possibility that precoding using the precoding matrix of Formula(33) or Formula (34), for example, is supported as a precoding method#A; and precoding using the precoding matrix taking θ=π/4 radians inFormula (15) or Formula (16), for example, is supported as a precodingmethod #B.

Assume that when generating the modulated signals of multiple streamswith respect to the terminal #p, the base station or AP selects aprecoding method between the precoding method #A and the precodingmethod #B, performs precoding (weight combining) according to theselected precoding method, and transmits the modulated signals.

At this time, the terminal #p transmits a modulated signal including“information about whether or not the terminal #p is able to receivemultiple modulated signals, execute demodulation, and obtain data whenthe base station or AP transmits multiple modulated signals to theterminal #p according to the precoding method #A” and “information aboutwhether or not the terminal #p is able to receive multiple modulatedsignals, execute demodulation, and obtain data when the base station orAP transmits multiple modulated signals to the terminal #p according tothe precoding method #B”. Additionally, by receiving this modulatedsignal, the base station or AP is able to learn “whether or not theterminal #p on the other end of communication supports the precodingmethod #A and the precoding method #B, and is able to demodulatemodulated signals”.

For example, the data 5301 related to “supported precoding methods” inFIG. 53 included in the reception capability notification symbols 2702transmitted by the terminal #p is configured as follows.

Assume that the data 5301 related to “supported precoding methods” ismade up of the 2 bits of bit m0 and bit m1. Additionally, the terminal#p transmits bit m0 and bit m1 to the base station or AP on the otherend of communication as the data 5301 related to “supported precodingmethods”.

For example, in the case in which the terminal #p is able to receive anddemodulate “a modulated signal generated by the base station or APaccording to the precoding method #A” (demodulation is supported), m0=1is set, and bit m0 is transmitted to the base station or AP on the otherend of communication as a part of the data 5301 related to “supportedprecoding methods”.

Also, in the case in which the terminal #p does not support demodulationeven if “a modulated signal generated by the base station or APaccording to the precoding method #A” is received, m0=0 is set, and bitm0 is transmitted to the base station or AP on the other end ofcommunication as a part of the data 5301 related to “supported precodingmethods”.

Also, for example, in the case in which the terminal #p is able toreceive and demodulate “a modulated signal generated by the base stationor AP according to the precoding method #B” (demodulation is supported),m1=1 is set, and bit m1 is transmitted to the base station or AP on theother end of communication as a part of the data 5301 related to“supported precoding methods”.

Also, in the case in which the terminal #p does not support demodulationeven if “a modulated signal generated by the base station or APaccording to the precoding method #B” is received, m1=0 is set, and bitm1 is transmitted to the base station or AP on the other end ofcommunication as a part of the data 5301 related to “supported precodingmethods”.

Next, specific examples of operation will be described hereinafter byciting a first example to a fifth example.

First Example

As the first example, suppose that the configuration of the receptionapparatus of the terminal #p is the configuration illustrated in FIG.19, and the reception apparatus of the terminal #p supports thefollowing, for example.

-   -   The reception, for example, of “communication scheme #A” and        “communication scheme #B” described in Embodiment 3 is        supported.    -   If the other end of communication transmits modulated signals of        multiple streams in “communication scheme #B” to the terminal        #p, the terminal #p supports the reception of such signals.        Also, in “communication scheme #A” and “communication scheme        #B”, if the other end of communication transmits a modulated        signal of a single stream to the terminal #p, the terminal #p        supports the reception of such a signal.    -   Additionally, in the case in which the other end of        communication performs phase change when transmitting modulated        signals of multiple streams to the terminal #p, the terminal #p        supports the reception of such signals.    -   The single-carrier scheme and the OFDM scheme are supported.    -   As the error-correcting coding scheme, the decoding of        “error-correcting coding scheme #C” and the decoding of        “error-correcting coding scheme #D” are supported.    -   The reception of “precoding method #A” and the reception of        “precoding method #B” described above are supported.

Thus, terminal #p having the configuration of FIG. 19 supporting theabove generates the reception capability notification symbols 2702adopting the configuration illustrated in FIG. 53 on the basis of therules described in Embodiment 3 and the description in the presentembodiment, and transmits the reception capability notification symbols2702 by following the procedure in FIG. 27, for example.

At this time, the terminal #p generates the reception capabilitynotification symbols 2702 adopting the configuration illustrated in FIG.53 in the transmission apparatus 3403 in FIG. 34, for example, andfollowing the procedure in FIG. 27, the transmission apparatus 3403 ofFIG. 34 transmits the reception capability notification symbols 2702adopting the configuration illustrated in FIG. 53.

Note that in the case of the first example, since the terminal #psupports the reception of “precoding method #A” and the reception of“precoding method #B”, bit m0 is set to 1 and bit m1 is set to 1 in thedata 5301 related to “supported precoding methods”.

The signal processor 155 of the base station (AP) in FIG. 22 acquires abaseband signal group 154 including the reception capabilitynotification symbols 2702 transmitted by terminal #p through thereception antenna group 151 and the radio section group 153.Additionally, the signal processor 155 of the base station (AP) in FIG.22 extracts the data included in the reception capability notificationsymbols 2702, and thereby learns that terminal #p supports the“communication scheme #A” and the “communication scheme #B” from thedata 3001 related to “supported schemes”.

Also, from the data 2901 related to “reception for multiple streamssupported/unsupported” in FIG. 53, the signal processor 155 of the basestation (AP) learns that “if the other end of communication transmitsmodulated signals of multiple streams to the terminal #p, the terminal#p supports the reception of such signals” and “if the other end ofcommunication transmits a modulated signal of a single stream in“communication scheme #A” and “communication scheme #B” to the terminal#p, the terminal #p supports the reception of such a signal”.

Additionally, from the data 2801 related to “demodulation of modulatedsignal with phase change supported/unsupported” in FIG. 53, the signalprocessor 155 of the base station (AP) learns that terminal #p “supportsdemodulation of modulated signal with phase change”.

From the data 3002 related to “multi-carrier schemesupported/unsupported” in FIG. 53, the signal processor 155 of the basestation (AP) learns that “the terminal #p supports the ‘single-carrierscheme’ and the ‘OFDM scheme’”.

From the data 3003 related to “supported error-correcting codingschemes” in FIG. 53, the signal processor 155 of the base station (AP)learns that the terminal #p “supports the decoding of ‘error-correctingcoding scheme #C’ and the decoding of ‘error-correcting coding scheme#D’”.

From the data 5301 related to “supported precoding methods” in FIG. 53,the signal processor 155 of the base station (AP) learns that theterminal #p “supports the reception of ‘precoding method #A’ and thereception of ‘precoding method #B’”.

Consequently, by having the base station or AP take into account thecommunication methods supported by the terminal #p, the communicationenvironment, and the like, and appropriately generate and transmitmodulated signals receivable by the terminal #p, an advantageous effectof improving the data transmission efficiency in the system includingthe base station or AP and the terminal #p may be obtained.

Second Example

As the second example, suppose that the reception apparatus of theterminal #p is the configuration illustrated in FIG. 35, and thereception apparatus of the terminal #p supports the following, forexample.

-   -   The reception, for example, of “communication scheme #A” and        “communication scheme #B” described in Embodiment 3 is        supported.    -   If the other end of communication transmits modulated signals of        multiple streams to the terminal #p, the terminal #p does not        support the reception of such signals.    -   Thus, in the case in which the other end of communication        performs phase change when transmitting modulated signals of        multiple streams to the terminal #p, the terminal #p does not        support the reception of such signals.    -   The single-carrier scheme and the OFDM scheme are supported.    -   As the error-correcting coding scheme, the decoding of        “error-correcting coding scheme #C” and the decoding of        “error-correcting coding scheme #D” are supported.    -   The reception of “precoding method #A” and the reception of        “precoding method #B” described above are not supported.

Thus, terminal #p having the configuration of FIG. 35 supporting theabove generates the reception capability notification symbols 2702adopting the configuration illustrated in FIG. 53 on the basis of therules described in Embodiment 3 and the description in the presentembodiment, and transmits the reception capability notification symbols2702 by following the procedure in FIG. 27, for example.

At this time, the terminal #p generates the reception capabilitynotification symbols 2702 adopting the configuration illustrated in FIG.53 in the transmission apparatus 3403 in FIG. 34, for example; andfollowing the procedure in FIG. 27, the transmission apparatus 3403 ofFIG. 34 transmits the reception capability notification symbols 2702adopting the configuration illustrated in FIG. 53.

The signal processor 155 of the base station (AP) in FIG. 22 acquires abaseband signal group 154 including the reception capabilitynotification symbols 2702 transmitted by terminal #p through thereception antenna group 151 and the radio section group 153.Additionally, the signal processor 155 of the base station (AP) in FIG.22 extracts the data included in the reception capability notificationsymbols 2702, and learns that the terminal #p supports the“communication scheme #A” and the “communication scheme #B” from thedata 3001 related to “supported schemes”.

Also, from the data 2901 related to “reception for multiple streamssupported/unsupported” in FIG. 53, the signal processor 155 of the basestation (AP) learns that “if the other end of communication transmitsmodulated signals of multiple streams to the terminal #p, the terminal#p does not support the reception of such signals”.

Consequently, since the data 2801 related to “demodulation of modulatedsignal with phase change supported/unsupported” in FIG. 53 is invalid,the signal processor 155 of the base station (AP) decides not totransmit a phase-changed modulated signal, and outputs a control signal157 including this information.

Also, since the data 5301 related to “supported precoding methods” inFIG. 53 is invalid, the signal processor 155 of the base station (AP)decides not to transmit the modulated signals of multiple streams, andoutputs a control signal 157 including this information.

From the data 3002 related to “multi-carrier schemesupported/unsupported” in FIG. 53, the signal processor 155 of the basestation (AP) learns that “the terminal #p supports the ‘single-carrierscheme’ and the ‘OFDM scheme’”.

From the data 3003 related to “supported error-correcting codingschemes” in FIG. 53, the signal processor 155 of the base station (AP)learns that the terminal #p “supports the decoding of ‘error-correctingcoding scheme #C’ and the decoding of ‘error-correcting coding scheme#D’”.

For example, the terminal #p is equipped with the configuration of FIG.35, and consequently, by executing operations as described above tocause the base station or AP not to transmit the modulated signals ofmultiple streams to the terminal #p, the base station or AP is able toappropriately transmit modulated signals that the terminal #p is able todemodulate and decode. With this arrangement, an advantageous effect ofimproved data transmission efficiency in the system including the basestation or AP and the terminal #p may be obtained.

Third Example

As the third example, suppose that the reception apparatus of theterminal #p is the configuration illustrated in FIG. 19, and thereception apparatus of the terminal #p supports the following, forexample.

-   -   The reception, for example, of “communication scheme #A” and        “communication scheme #B” described in Embodiment 3 is        supported.    -   If the other end of communication transmits modulated signals of        multiple streams in “communication scheme #B” to the terminal        #p, the terminal #p supports the reception of such signals.        Also, in “communication scheme #A” and “communication scheme        #B”, if the other end of communication transmits a modulated        signal of a single stream to the terminal #p, the terminal #p        supports the reception of such a signal.    -   Additionally, in the case in which the other end of        communication performs phase change when transmission modulated        signals of multiple streams to the terminal #p, the terminal #p        supports the reception of such signals.    -   The single-carrier scheme and the OFDM scheme are supported.    -   As the error-correcting coding scheme, the decoding of        “error-correcting coding scheme #C” and the decoding of        “error-correcting coding scheme #D” are supported.    -   The reception of “precoding method #A” described above is        supported. In other words, in the third example, the reception        of the “precoding method #B” described above is not supported.

Thus, terminal #p having the configuration of FIG. 19 supporting theabove generates the reception capability notification symbols 2702adopting the configuration illustrated in FIG. 53 on the basis of therules described in Embodiment 3 and the description in the presentembodiment, and transmits the reception capability notification symbols2702 by following the procedure in FIG. 27, for example.

At this time, the terminal #p generates the reception capabilitynotification symbols 2702 adopting the configuration illustrated in FIG.53 in the transmission apparatus 3403 in FIG. 34, for example, andfollowing the procedure in FIG. 27, the transmission apparatus 3403 ofFIG. 34 transmits the reception capability notification symbols 2702adopting the configuration illustrated in FIG. 53.

Note that in the case of the third example, since the terminal #psupports the reception of “precoding method #A” and does not support thereception of “precoding method #B”, bit m0 is set to 1 and bit m1 is setto 0 in the data 5301 related to “supported precoding methods”.

The signal processor 155 of the base station (AP) in FIG. 22 acquires abaseband signal group 154 including the reception capabilitynotification symbols 2702 transmitted by terminal #p through thereception antenna group 151 and the radio section group 153.Additionally, the signal processor 155 of the base station (AP) in FIG.22 extracts the data included in the reception capability notificationsymbols 2702, and thereby learns that terminal #p supports the“communication scheme #A” and the “communication scheme #B” from thedata 3001 related to “supported schemes”.

Also, from the data 2901 related to “reception for multiple streamssupported/unsupported” in FIG. 53, the signal processor 155 of the basestation (AP) learns that “if the other end of communication transmitsmodulated signals of multiple streams to the terminal #p, the terminal#p supports the reception of such signals” and “if the other end ofcommunication transmits a modulated signal of a single stream in“communication scheme #A” and “communication scheme B” to the terminal#p, the terminal #p supports the reception of such a signal”.

Additionally, from the data 2801 related to “demodulation of modulatedsignal with phase change supported/unsupported” in FIG. 53, the signalprocessor 155 of the base station (AP) learns that terminal #p “supportsdemodulation of modulated signal with phase change”.

From the data 3002 related to “multi-carrier schemesupported/unsupported” in FIG. 53, the signal processor 155 of the basestation (AP) learns that “the terminal #p supports the ‘single-carrierscheme’ and the ‘OFDM scheme’”.

From the data 3003 related to “supported error-correcting codingschemes” in FIG. 53, the signal processor 155 of the base station (AP)learns that the terminal #p “supports the decoding of ‘error-correctingcoding scheme #C’ and the decoding of ‘error-correcting coding scheme#D’”.

From the data 5301 related to “supported precoding methods” in FIG. 53,the signal processor 155 of the base station (AP) learns that theterminal #p “supports the reception of ‘precoding method #A’”.

Consequently, by having the base station or AP take into account thecommunication methods supported by the terminal #p, the communicationenvironment, and the like, and appropriately generate and transmitmodulated signals receivable by the terminal #p, an advantageous effectof improving the data transmission efficiency in the system includingthe base station or AP and the terminal #p may be obtained.

Fourth Example

As the fourth example, suppose that the configuration of the receptionapparatus of the terminal #p is the configuration illustrated in FIG.19, and the reception apparatus of the terminal #p supports thefollowing, for example.

-   -   The reception, for example, of “communication scheme #A” and        “communication scheme #B” described in Embodiment 3 is        supported.    -   If the other end of communication transmits modulated signals of        multiple streams in “communication scheme #B” to the terminal        #p, the terminal #p supports the reception of such signals.        Also, in “communication scheme #A” and “communication scheme        #B”, if the other end of communication transmits a modulated        signal of a single stream to the terminal #p, the terminal #p        supports the reception of such a signal.    -   The single-carrier scheme is supported. Note that in the        single-carrier scheme, assume that the base station on the other        end of communication does not support “performing phase change        in the case of modulated signals of multiple streams”, and also        does not support “performing precoding”.    -   Consequently, in the case in which the other end of        communication performs phase change when transmitting modulated        signals of multiple streams to the terminal #p, the terminal #p        does not support the reception of such signals.    -   As the error-correcting coding scheme, the decoding of        “error-correcting coding scheme #C” and the decoding of        “error-correcting coding scheme #D” are supported.    -   The reception of “precoding method #A” described above is        supported.

Thus, terminal #p having the configuration of FIG. 19 supporting theabove generates the reception capability notification symbols 2702adopting the configuration illustrated in FIG. 53 on the basis of therules described in Embodiment 3 and the description in the presentembodiment, and transmits the reception capability notification symbols2702 by following the procedure in FIG. 27, for example.

At this time, terminal #p generates the reception capabilitynotification symbols 2702 illustrated in FIG. 53 in the transmissionapparatus 3403 of FIG. 34, for example, and following the procedure inFIG. 27, the transmission apparatus 3403 of FIG. 34 transmits thereception capability notification symbols 2702 illustrated in FIG. 53.

The signal processor 155 of the base station (AP) in FIG. 22 acquires abaseband signal group 154 including the reception capabilitynotification symbols 2702 transmitted by terminal #p through thereception antenna group 151 and the radio section group 153.Additionally, the signal processor 155 of the base station (AP) in FIG.22 extracts the data included in the reception capability notificationsymbols 2702, and from the data 2901 related to “reception for multiplestreams supported/unsupported” in FIG. 53, learns that “if the other endof communication transmits modulated signals of multiple streams to theterminal #p, the terminal #p supports the reception of such signals” and“if the other end of communication transmits a modulated signal of asingle stream in “communication scheme #A” and “communication scheme #B”to the terminal #p, the terminal #p supports the reception of such asignal”.

From the data 3002 related to “multi-carrier schemesupported/unsupported” in FIG. 53, the signal processor 155 of the basestation (AP) learns that “the terminal #p supports the ‘single-carrierscheme’”.

Consequently, since the data 2801 related to “demodulation of modulatedsignal with phase change supported/unsupported” in FIG. 53 is invalid,the signal processor 155 of the base station (AP) decides not totransmit a phase-changed modulated signal, and outputs a control signal157 including this information.

Also, since the data 5301 related to “supported precoding methods” inFIG. 53 is invalid, the signal processor 155 of the base station (AP)outputs control information 157 indicating that “precoding is notexecuted”.

From the data 3003 related to “supported error-correcting codingschemes” in FIG. 53, the signal processor 155 of the base station (AP)learns that the terminal #p “supports the decoding of ‘error-correctingcoding scheme #C’ and the decoding of ‘error-correcting coding scheme#D’”.

Consequently, by having the base station or AP take into account thecommunication methods supported by the terminal #p, the communicationenvironment, and the like, and appropriately generate and transmitmodulated signals receivable by the terminal #p, an advantageous effectof improving the data transmission efficiency in the system includingthe base station or AP and the terminal #p may be obtained.

Fifth Example

As the fifth example, suppose that the reception apparatus of theterminal #p is the configuration illustrated in FIG. 35, and thereception apparatus of the terminal #p supports the following, forexample.

-   -   The reception, for example, of “communication scheme #A”        described in Embodiment 3 is supported.    -   Consequently, if the other end of communication transmits        modulated signals of multiple streams to the terminal #p, the        terminal #p does not support the reception of such signals.    -   Thus, in the case in which the other end of communication        performs phase change when transmitting modulated signals for        multiple streams to the terminal #p, the terminal #p does not        support the reception of such signals.    -   Furthermore, if the other end of communication transmits        modulated signals of multiple streams generated using “precoding        method #A”, the terminal #p does not support the reception of        such signals. Also, if the other end of communication transmits        modulated signals of multiple streams generated using “precoding        method #B”, the terminal #p does not support the reception of        such signals.    -   Only the single-carrier scheme is supported.    -   As the error-correcting coding scheme, only the decoding of        “error-correcting coding scheme #C” is supported.

Thus, terminal #p having the configuration of FIG. 35 supporting theabove generates the reception capability notification symbols 2702adopting the configuration illustrated in FIG. 53 on the basis of therules described in Embodiment 3 and the description in the presentembodiment, and transmits the reception capability notification symbols2702 by following the procedure in FIG. 27, for example.

At this time, the terminal #p generates the reception capabilitynotification symbols 2702 adopting the configuration illustrated in FIG.53 in the transmission apparatus 3403 in FIG. 34, for example, andfollowing the procedure in FIG. 27, the transmission apparatus 3403 ofFIG. 34 transmits the reception capability notification symbols 2702adopting the configuration illustrated in FIG. 53.

The signal processor 155 of the base station (AP) in FIG. 22 acquires abaseband signal group 154 including the reception capabilitynotification symbols 2702 transmitted by terminal #p through thereception antenna group 151 and the radio section group 153.Additionally, the signal processor 155 of the base station (AP) in FIG.22 extracts the data included in the reception capability notificationsymbols 2702, and learns that terminal #p supports the “communicationscheme #B” from the data 3001 related to “supported schemes”.

Consequently, since the data 2801 related to “demodulation of modulatedsignal with phase change supported/unsupported” in FIG. 53 is invalid,and the communication scheme #A is supported, the signal processor 155of the base station (AP) decides not to transmit a phase-changedmodulated signal, and outputs a control signal 157 including thisinformation. This is because the communication scheme #A does notsupport the transmitting and reception of modulated signals for multiplestreams.

Also, since the data 2901 related to “reception for multiple streamssupported/unsupported” in FIG. 53 is invalid, and the communicationscheme #A is supported, the signal processor 155 of the base station(AP) decides not to transmit modulated signals for multiple streams tothe terminal #p, and outputs a control signal 157 including thisinformation. This is because the communication scheme #A does notsupport the transmitting and reception of modulated signals for multiplestreams.

Additionally, since the communication scheme #A is supporting, the data5301 related to “supported precoding methods” in FIG. 53 is invalid, andthe signal processor 155 of the base station (AP) decides not totransmit the modulated signals of multiple streams, and outputs acontrol signal 157 including this information.

Additionally, since the data 3003 related to “supported error-correctingcoding schemes” in FIG. 53 is invalid, and the communication method #Ais supported, the signal processor 155 of the base station (AP) decidesto use “error-correcting coding scheme #C”, and outputs a control signal157 including this information. This is because the communication scheme#A supports the “error-correcting coding scheme #C”.

For example, as in FIG. 35, “communication scheme #A” is supported, andconsequently, by executing operations as described above to cause thebase station or AP not to transmit modulated signals for multiplestreams to the terminal #p, the base station or AP is able toappropriately transmit modulated signals in “communication scheme #A”.As a result, an advantageous effect of improved data transmissionefficiency in the system including the base station or AP and theterminal #p may be obtained.

As above, the base station or AP acquires information related to thedemodulation schemes supported by the terminal #p from the terminal #pon the other end of communication with the base station or AP, and onthe basis of the information, decides the number of modulated signals,the modulated signal communication scheme, the signal processing methodof the modulated signal, and the like, and thereby is able toappropriately transmit modulated signals receivable by the terminal #p.As a result, an advantageous effect of improved data transmissionefficiency in the system including the base station or AP and theterminal #p may be obtained.

At this time, by including multiple pieces of information in thereception capability notification symbols 2702 like in FIG. 53, forexample, the base station or AP is able to determine thevalidity/invalidity of the information included in the receptioncapability notification symbols 2702 easily. This arrangement has anadvantage of enabling fast determination of the modulated signal schemeand/or the signal processing method and the like for transmission.

Additionally, on the basis of the content of the information of thereception capability notification symbols 2702 transmitted by eachterminal #p, the base station or AP is able to transmit modulatedsignals to each terminal #p by a favorable transmission method, therebyimproving the data transmission efficiency.

Also, the base station or AP in the present embodiment adopts theconfiguration in FIG. 1, and communicates with multiple terminals. Thereception capability (the supported demodulation schemes) of themultiple terminals on the other end of communication with the basestation or AP in FIG. 1 may be the same or different from each other.Each of the multiple terminals transmits reception capabilitynotification symbols including information related to the supporteddemodulated schemes. The base station or AP acquires the informationrelated to the supported demodulation schemes from each terminal, and onthe basis of this information, decides the number of modulated signals,the modulated signal communication scheme, the signal processing methodof the modulated signal, and the like, and thereby is able to transmitmodulated signals receivable by each terminal on the basis of thereception capability (supported demodulated schemes) for each terminal.With this arrangement, an advantageous effect of improved datatransmission efficiency in the system including the base station or APand multiple terminals may be obtained. Note that the base station or APuses certain time intervals or certain frequencies to transmit modulatedsignals to multiple terminals, and in this case, transmits one or moremodulated signals to each terminal. Consequently, each terminal may alsotransmit reception capability notification symbols as described above tothe base station or AP.

Note that the method of configuring the information of the receptioncapability notification symbols described in the present embodiment isan example, and the method of configuring the information of thereception capability notification symbols is not limited thereto. Also,the transmission procedure by which terminal #p transmits the receptioncapability notification symbols to the base station or AP and thedescription of the present embodiment regarding the transmission timingsare merely one example, and the configuration is not limited thereto.

Also, the present embodiment describes an example in which multipleterminals transmit the reception capability notification symbols, butthe method of configuring the information of the reception capabilitynotification symbols transmitted by the multiple terminals may bedifferent or the same among the terminals. Also, the transmissionprocedure and the transmission timing by which the multiple terminalstransmit the reception capability notification symbols may be differentor the same among the terminals.

(Supplement 4)

In this specification, when the transmission apparatus of the basestation or AP transmits a modulated signal of a single stream, FIG. 35is illustrated as an example of the configuration of the receptionapparatus of the terminal #p on the other end of communication with thebase station or AP, but the configuration of terminal #p that receivesthe modulated signal of a single stream is not limited to FIG. 35. Forexample, the reception apparatus of the terminal #p may also have aconfiguration equipped with multiple reception antennas. For example, inFIG. 19, in the case in which the modulated signal u2 channel estimators1905_2 and 1907_2 do not operate, the channel estimators operate withrespect to a single modulated signal, and thus even with such aconfiguration, the modulated signal of a single stream may be received.

Consequently, in the description in this specification, even if theoperation of the embodiment described using FIG. 35 has the receptionapparatus configuration of the above description instead of FIG. 19,similar operation may be achieved, and similar advantageous effects maybe obtained.

Also, in this specification, the configurations of FIGS. 28, 29, 30, and53 are described as examples of the configuration of receptioncapability notification symbols transmitted by the terminal #p. At thistime, an advantageous effect of the reception capability notificationsymbols “including multiple pieces of information (multiple pieces ofdata)” is described. In the following, methods of transmitting the“multiple pieces of information (multiple pieces of data)” included inthe reception capability notification symbols transmitted by theterminal #p will be described.

Exemplary Configuration 1:

For example, among the data 2801 related to “demodulation of modulatedsignal with phase change supported/unsupported”, the data 2901 relatedto “reception for multiple streams supported/unsupported”, the data 3001related to “supported schemes”, the data 3002 related to “multi-carrierscheme supported/unsupported”, and the data 3003 related to “supportederror-correcting coding schemes” in FIG. 30, at least two or more piecesof data (information) are transmitted using the same frame or the samesubframe.

Exemplary Configuration 2:

For example, among the data 2801 related to “demodulation of modulatedsignal with phase change supported/unsupported”, the data 2901 relatedto “reception for multiple streams supported/unsupported”, the data 3001related to “supported schemes”, the data 3002 related to “multi-carrierscheme supported/unsupported”, the data 3003 related to “supportederror-correcting coding schemes”, and the data 5301 related to“supported precoding methods” in FIG. 53, at least two or more pieces ofdata (information) are transmitted using the same frame or the samesubframe.

At this point, “frame” and “subframe” will be described.

FIG. 54 is a diagram illustrating an example of the configuration of aframe. In FIG. 54, the horizontal axis is time. For example, in FIG. 54,assume that the frame includes a preamble 8001, control informationsymbols 8002, and data symbols 8003. However, the frame does not have tobe configured to include all three of the above. For example, the framemay “at least include the preamble 8001”, “at least include the controlinformation symbols 8002”, “at least include the preamble 8001 and thedata symbols 8003”, “at least include the preamble 8001 and the controlinformation symbols 8002”, “at least include the preamble 8001 and thedata symbols 8003”, or “at least include the preamble 8001, the controlinformation symbols 8002, and the data symbols 8003”.

Additionally, the terminal #p transmits the reception capabilitynotification symbols using the symbols of any of the preamble 8001, thecontrol information symbols 8002, or the data symbols 8003.

Note that FIG. 54 may also be called a subframe. Also, a term other thanframe or subframe may be used.

Using a method like the above, by having the terminal #p transmit atleast two or more pieces of information included in the receptioncapability notification symbols, the advantageous effects described inEmbodiment 3, Embodiment 5, Embodiment 11, and the like may be obtained.

Exemplary Configuration 3:

For example, among the data 2801 related to “demodulation of modulatedsignal with phase change supported/unsupported”, the data 2901 relatedto “reception for multiple streams supported/unsupported”, the data 3001related to “supported schemes”, the data 3002 related to “multi-carrierscheme supported/unsupported”, and the data 3003 related to “supportederror-correcting coding schemes” in FIG. 30, at least two or more piecesof data (information) are transmitted using the same packet.

Exemplary Configuration 4:

For example, among the data 2801 related to “demodulation of modulatedsignal with phase change supported/unsupported”, the data 2901 relatedto “reception for multiple streams supported/unsupported”, the data 3001related to “supported schemes”, the data 3002 related to “multi-carrierscheme supported/unsupported”, the data 3003 related to “supportederror-correcting coding schemes”, and the data 5301 related to“supported precoding methods” in FIG. 53, at least two or more pieces ofdata (information) are transmitted using the same packet.

Consider the frame in FIG. 54. Additionally, assume that the frame “atleast includes the preamble 8001 and the data symbols 8003”, “at leastincludes the control information symbols 8002 and the data symbols8003”, or “at least includes the preamble 8001, the control informationsymbols 8002, and the data symbols 8003”.

At this time, there are two methods of transmitting a packet, forexample.

First Method:

The data symbols 8003 are included in multiple packets. In this case, atleast two pieces of data (information) included in the receptioncapability notification symbols are transmitted by the data symbols8003.

Second Method:

The packet is transmitted by the data symbols of multiple frames. Inthis case, at least two or more pieces of data (information) included inthe reception capability notification symbols are transmitted usingmultiple frames.

Using a method like the above, by having the terminal #p transmit atleast two or more pieces of data (information) included in the receptioncapability notification symbols, the advantageous effects described inEmbodiment 3, Embodiment 5, Embodiment 11, and the like may be obtained.

Note that in FIG. 54, the term “preamble” is used, but the term is notlimited thereto. The “preamble” is assumed to include at least one ormore symbols or signals of “a symbol or signal by which the other end ofcommunication detects a modulated signal”, “a symbol or signal by whichthe other end of communication executes channel estimation (propagationenvironment estimation)”, “a symbol or signal by which the other end ofcommunication executes time synchronization”, “a symbol or signal bywhich the other end of communication executes frequencysynchronization”, and “a symbol or signal by which the other end ofcommunication executes frequency offset estimation”.

Also, in FIG. 54, the term “control information symbols” is used, butthe term is not limited thereto. The “control information symbols” areassumed to be symbols including at least one or more pieces ofinformation of “information about the error-correcting coding scheme forgenerating data symbols”, “information about the modulation scheme forgenerating data symbols”, “information about the number of symbolsincluded in the data symbols”, “information related to the data symboltransmission method”, “information other than data symbols that needs tobe transmitted to the other end of communication”, and “informationother than data symbols”.

Note that the order in which the preamble 8001, the control informationsymbols 8002, and the data symbols 8003 are transmitted, or in otherwords, the frame configuration method, is not limited to FIG. 54.

In Embodiment 3, Embodiment 5, Embodiment 11, and the like, the terminal#p is described as transmitting the reception capability notificationsymbols, and the other end of communication with the terminal #p isdescribed as a base station or AP, but the configuration is not limitedthereto. For example, the other end of communication with the basestation or AP may be the terminal #p, and the base station or AP maytransmit reception capability notification symbols to the terminal #p onthe other end of communication. Alternatively, the other end ofcommunication with the terminal #p may be another terminal, and theterminal #p may transmit reception capability notification symbols tothe other terminal on the other end of communication. Alternatively, theother end of communication with the base station or AP may be anotherbase station or AP, and the base station or AP may transmit receptioncapability notification symbols to the other base station or AP on theother end of communication.

Embodiment 12

In Embodiment 1 to Embodiment 11, Supplement 1 to Supplement 4, and thelike, the phase changer 305B, the phase changer 305A, the phase changer3801B, and the phase changer 3801A in FIGS. 3, 4, 26, 38, 39, 40, 41,42, 43, 44, 45, 46, 47, 48, 49, and the like are described using Formula(2), Formula (44), and the like, for example, while in addition, it isnoted that the values of the phase change values do not have to be basedon these formulas, and also that “it is sufficient to change the phaseperiodically or regularly”.

In the present embodiment, another example of being “sufficient tochange the phase periodically or regularly” will be described. FIG. 55is a diagram illustrating an example of carrier groups of modulatedsignals transmitted by a base station or AP. In FIG. 55, the horizontalaxis indicates frequency (carrier), while the vertical axis indicatestime.

For example, like in FIG. 55, consider a first carrier group includingcarrier #1 to carrier #5, a second carrier group including carrier #6 tocarrier #10, a third carrier group including carrier #11 to carrier #15,a fourth carrier group including carrier #16 to carrier #20, and a fifthcarrier group including carrier #21 to carrier #25. Assume that, totransmit data to a certain terminal (certain user) (terminal #p), thebase station or AP uses the first carrier group, the second carriergroup, the third carrier group, the fourth carrier group, and the fifthcarrier group.

Assume that Yp(i) is the phase change value used by the phase changer305A, yp(i) is the phase change value used by the phase changer 305B,Vp(i) is the phase change value used by the phase changer 3801A, andvp(i) is the phase change value used by the phase changer 3801B in FIGS.3, 4, 26, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, and the like.

At this time, assume that in the phase changer 305A, phase change isexecuted on symbols belonging to the first carrier group of FIG. 55,using e^(j×E1) as the phase change value Yp(i). Note that E1 is assumedto be a real number. For example, E1 is 0 (radians)≤E1<2×π (radians).

Additionally, assume that in the phase changer 305A, phase change isexecuted on symbols belonging to the second carrier group of FIG. 55,using e^(j×E2) as the phase change value Yp(i). Note that E2 is assumedto be a real number. For example, E2 is 0 (radians)≤E2<2×π (radians).

Assume that in the phase changer 305A, phase change is executed onsymbols belonging to the third carrier group of FIG. 55, using e^(j×E3)as the phase change value Yp(i). Note that E3 is assumed to be a realnumber. For example, E3 is 0 (radians)≤E3<2×π (radians).

Assume that in the phase changer 305A, phase change is executed onsymbols belonging to the fourth carrier group of FIG. 55, using e^(j×E4)as the phase change value Yp(i). Note that E4 is assumed to be a realnumber. For example, E4 is 0 (radians)≤E4<2×π (radians).

Assume that in the phase changer 305A, phase change is executed onsymbols belonging to the fifth carrier group of FIG. 55, using e^(j×E5)as the phase change value Yp(i). Note that E5 is assumed to be a realnumber. For example, E5 is 0 (radians)≤E5<2×π (radians).

As a first example, there is a method in which “E1≠E2, and E1≠E3, andE1≠E4, and E1≠E5, and E2≠E3, and E2≠E4, and E2≠E5, and E3≠E4, and E3≠E5,and E4≠E5” holds. When generalized, the method is one in which “x is aninteger equal to 1 or greater, y is an integer equal to 1 or greater,x≠y holds, and for all x and y satisfying these conditions, Ex≠Eyholds”.

As a second example, there is a method in which “E1≠E2, or E1≠E3, orE1≠E4, or E1≠E5, or E2≠E3, or E2≠E4, or E2≠E5, or E3≠E4, or E3≠E5, orE4≠E5” holds. When generalized, the method is one in which “there existsa set of x, y such that x is an integer equal to 1 or greater, y is aninteger equal to 1 or greater, x≠y holds, and Ex≠Ey holds”.

Also, assume that in the phase changer 305B, phase change is executed onsymbols belonging to the first carrier group of FIG. 55, using e^(j×F1)as the phase change value yp(i). Note that F1 is assumed to be a realnumber. For example, F1 is 0 (radians)≤F1<2×π (radians).

Additionally, assume that in the phase changer 305B, phase change isexecuted on symbols belonging to the second carrier group of FIG. 55,using e^(j×F2) as the phase change value yp(i). Note that F2 is assumedto be a real number. For example, F2 is 0 (radians)≤F2<2×π (radians).

Assume that in the phase changer 305B, phase change is executed onsymbols belonging to the third carrier group of FIG. 55, using e^(j×F3)as the phase change value yp(i). Note that F3 is assumed to be a realnumber. For example, F3 is 0 (radians)≤F3<2×π (radians).

Assume that in the phase changer 305B, phase change is executed onsymbols belonging to the fourth carrier group of FIG. 55, using e^(j×F4)as the phase change value yp(i). Note that F4 is assumed to be a realnumber. For example, F4 is 0 (radians)≤F4<2×π (radians).

Assume that in the phase changer 305B, phase change is executed onsymbols belonging to the fifth carrier group of FIG. 55, using e^(j×F5)as the phase change value yp(i). Note that F5 is assumed to be a realnumber. For example, F5 is 0 (radians)≤F5<2×π (radians).

As a first example, there is a method in which “F1≠F2, and F1≠F3, andF1≠F4, and F1≠F5, and F2≠F3, and F2≠F4, and F2≠F5, and F3≠F4, and F3≠F5,and F4≠F5” holds. When generalized, the method is one in which “x is aninteger equal to 1 or greater, y is an integer equal to 1 or greater,x≠y holds, and for all x and y satisfying these conditions, Fx≠Fyholds”.

As a second example, there is a method in which “F1≠F2, or F1≠F3, orF1≠F4, or F1≠F5, or F2≠F3, or F2≠F4, or F2≠F5, or F3≠F4, or F3≠F5, orF4≠F5” holds. When generalized, the method is one in which “there existsa set of x, y such that x is an integer equal to 1 or greater, y is aninteger equal to 1 or greater, x≠y holds, and Fx≠Fy holds”.

Also, assume that in the phase changer 3801A, phase change is executedon symbols belonging to the first carrier group of FIG. 55, usinge^(j×G1) as the phase change value Vp(i). Note that G1 is assumed to bea real number. For example, G1 is 0 (radians)≤G1<2×π (radians).

Also, assume that in the phase changer 3801A, phase change is executedon symbols belonging to the second carrier group of FIG. 55, usinge^(j×G2) as the phase change value Vp(i). Note that G2 is assumed to bea real number. For example, G2 is 0 (radians)≤G2<2×π (radians).

Assume that in the phase changer 3801A, phase change is executed onsymbols belonging to the third carrier group of FIG. 55, using e^(j×G3)as the phase change value Vp(i). Note that G3 is assumed to be a realnumber. For example, G3 is 0 (radians)≤G3<2×π (radians).

Assume that in the phase changer 3801A, phase change is executed onsymbols belonging to the fourth carrier group of FIG. 55, using e^(j×G4)as the phase change value Vp(i). Note that G4 is assumed to be a realnumber. For example, G4 is 0 (radians)≤G4<2×π (radians).

Assume that in the phase changer 3801A, phase change is executed onsymbols belonging to the fifth carrier group of FIG. 55, using e^(j×G5)as the phase change value Vp(i). Note that G5 is assumed to be a realnumber. For example, G5 is 0 (radians)≤G5<2×π (radians).

As a first example, there is a method in which “G1≠G2, and G1≠G3, andG1≠G4, and G1≠G5, and G2≠G3, and G2≠G4, and G2≠G5, and G3≠G4, and G3≠G5,and G4≠G5” holds. When generalized, the method is one in which “x is aninteger equal to 1 or greater, y is an integer equal to 1 or greater,x≠y holds, and for all x and y satisfying these conditions, Gx≠Gyholds”.

As a second example, there is a method in which “G1≠G2, or G1≠G3, orG1≠G4, or G1≠G5, or G2≠G3, or G2≠G4, or G2≠G5, or G3≠G4, or G3≠G5, orG4≠G5” holds. When generalized, the method is one in which “there existsa set of x, y such that x is an integer equal to 1 or greater, y is aninteger equal to 1 or greater, x≠y holds, and Gx≠Gy holds”.

Also, assume that in the phase changer 3801B, phase change is executedon symbols belonging to the first carrier group of FIG. 55, usinge^(j×H1) as the phase change value vp(i). Note that H1 is assumed to bea real number. For example, H1 is 0 (radians)≤H1<2×π (radians).

Additionally, assume that in the phase changer 3801B, phase change isexecuted on symbols belonging to the second carrier group of FIG. 55,using e^(j×H2) as the phase change value vp(i). Note that H2 is assumedto be a real number. For example, H2 is 0 (radians)≤H2<2×π (radians).

Assume that in the phase changer 3801B, phase change is executed onsymbols belonging to the third carrier group of FIG. 55, using e^(j×H3)as the phase change value vp(i). Note that H3 is assumed to be a realnumber. For example, H3 is 0 (radians)≤H3<2×π (radians).

Assume that in the phase changer 3801B, phase change is executed onsymbols belonging to the fourth carrier group of FIG. 55, using e^(j×H4)as the phase change value vp(i). Note that H4 is assumed to be a realnumber. For example, H4 is 0 (radians)≤H4<2×π (radians).

Assume that in the phase changer 3801B, phase change is executed onsymbols belonging to the fifth carrier group of FIG. 55, using e^(j×H5)as the phase change value vp(i). Note that H5 is assumed to be a realnumber. For example, H5 is 0 (radians)≤H5<2×π (radians).

As a first example, there is a method in which “H1≠H2, and H1≠H3, andH1≠H4, and H1≠H5, and H2≠H3, and H2≠H4, and H2≠H5, and H3≠H4, and H3≠H5,and H4≠H5” holds. When generalized, the method is one in which “x is aninteger equal to 1 or greater, y is an integer equal to 1 or greater,x≠y holds, and for all x and y satisfying these conditions, Hx≠Hyholds”.

As a second example, there is a method in which “H1≠H2, or H1≠H3, orH1≠H4, or H1≠H5, or H2≠H3, or H2≠H4, or H2≠H5, or H3≠H4, or H3≠H5, orH4≠H5” holds. When generalized, the method is one in which “there existsa set of x, y such that x is an integer equal to 1 or greater, y is aninteger equal to 1 or greater, x≠y holds, and Hx≠Hy holds”.

Note that although the first carrier group to the fifth carrier groupexist in FIG. 55, the number of existing carrier groups is not limitedto 5, and it is possible to carry out the embodiment similarly insofaras there are 2 or more carrier groups. Also, the carrier groups may beset to 1. For example, one or more carrier groups may be configured toexist, on the basis of communication conditions, feedback informationfrom a terminal, and the like. When the carrier group is 1, phase changeis not executed. Like the example in FIG. 55, each carrier group mayalso be set to a fixed number of values.

Also, a configuration is taken in which all of the first carrier group,the second carrier group, the third carrier group, the fourth carriergroup, and the fifth carrier group are provided with five carriers, butthe configuration is not limited thereto. Consequently, it is sufficientfor a carrier group to be provided with one or more carriers.Additionally, different carrier groups may have the same or differentnumbers of provided carriers. For example, in FIG. 55, the number ofcarriers provided in the first carrier group is 5, and the number ofcarriers provided in the second carrier group is also 5 (the same). As adifferent example, the number of carriers provided in the first carriergroup of FIG. 55 may be set to 5, while the number of carriers providedin the second carrier group may be set to a different number such as 10.

FIG. 56 is a diagram illustrating a different example from FIG. 55 ofcarrier groups of modulated signals transmitted by a base station or AP.Note that in FIG. 56, the horizontal axis indicates frequency (carrier),while the vertical axis indicates time.

A first carrier group_1 includes from carrier #1 to carrier #5, and fromtime $1 to time $3. A second carrier group_1 includes from carrier #6 tocarrier #10, and from time $1 to time $3. A third carrier group_1includes from carrier #11 to carrier #15, and from time $1 to time $3. Afourth carrier group_1 includes from carrier #16 to carrier #20, andfrom time $1 to time $3. A fifth carrier group_1 includes from carrier#21 to carrier #25, and from time $1 to time $3.

A first carrier group_2 includes from carrier #1 to carrier #5, and fromtime $4 to time $9. A second carrier group_2 includes from carrier #6 tocarrier #10, and from time $4 to time $9. A third carrier group_2includes from carrier #11 to carrier #15, and from time $4 to time $9. Afourth carrier group_2 includes from carrier #16 to carrier #20, andfrom time $4 to time $9. A fifth carrier group_2 includes from carrier#21 to carrier #25, and from time $4 to time $9.

A first carrier group_3 includes from carrier #1 to carrier #25, andfrom time $10 to time $11.

A first carrier group_4 includes from carrier #1 to carrier #10, andfrom time $12 to time $14. A second carrier group_4 includes fromcarrier #11 to carrier #15, and from time $12 to time $14. A thirdcarrier group_4 includes from carrier #16 to carrier #25, and from time$12 to time $14.

In FIG. 56, assume that, to transmit data to a certain terminal (certainuser) (terminal #p), the base station or AP uses from carrier #1 tocarrier #25, from time $1 to time $14.

Assume that Yp(i) is the phase change value used by the phase changer305A, yp(i) is the phase change value used by the phase changer 305B,Vp(i) is the phase change value used by the phase changer 3801A, andvp(i) is the phase change value used by the phase changer 3801B in FIGS.3, 4, 26, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, and the like.

At this time, assume that in the phase changer 305A, phase change isexecuted on symbols belonging to the first carrier group_1 of FIG. 56,using e^(j×E11) as the phase change value Yp(i). Note that E11 isassumed to be a real number. For example, E11 is 0 (radians)≤E11<2×π(radians).

Additionally, assume that in the phase changer 305A, phase change isexecuted on symbols belonging to the second carrier group_1 of FIG. 56,using e^(j×E21) as the phase change value Yp(i). Note that E21 isassumed to be a real number. For example, E21 is 0 (radians)≤E21<2×π(radians).

Assume that in the phase changer 305A, phase change is executed onsymbols belonging to the third carrier group_1 of FIG. 56, usinge^(j×E31) as the phase change value Yp(i). Note that E31 is assumed tobe a real number. For example, E31 is 0 (radians)≤E31<2×π (radians).

Assume that in the phase changer 305A, phase change is executed onsymbols belonging to the fourth carrier group_1 of FIG. 56, usinge^(j×E41) as the phase change value Yp(i). Note that E41 is assumed tobe a real number. For example, E41 is 0 (radians)≤E41<2×π (radians).

Assume that in the phase changer 305A, phase change is executed onsymbols belonging to the fifth carrier group_1 of FIG. 56, usinge^(j×E51) as the phase change value Yp(i). Note that E51 is assumed tobe a real number. For example, E51 is 0 (radians)≤E51<2×π (radians).

As a first example, there is a method in which “E11≠E21, and E11≠E31,and E11≠E41, and E11≠E51, and E21≠E31, and E21≠E41, and E21≠E51, andE31≠E41, and E31≠E51, and E41≠E51” holds. When generalized, the methodis one in which “x is an integer equal to 1 or greater, y is an integerequal to 1 or greater, x≠y holds, and for all x and y satisfying theseconditions, Ex1≠Ey1 holds”.

As a second example, there is a method in which “E11≠E21, or E11≠E31, orE11≠E41, or E11≠E51, or E21≠E31, or E21≠E41, or E21≠E51, or E31≠E41, orE31≠E51, or E41≠E51” holds. When generalized, the method is one in which“there exists a set of x, y such that x is an integer equal to 1 orgreater, y is an integer equal to 1 or greater, x≠y holds, and Ex1≠Ey1holds”.

Also, assume that in the phase changer 305B, phase change is executed onsymbols belonging to the first carrier group_1 of FIG. 56, usinge^(j×F11) as the phase change value yp(i). Note that F11 is assumed tobe a real number. For example, F11 is 0 (radians)≤F11<2×π (radians).

Additionally, assume that in the phase changer 305B, phase change isexecuted on symbols belonging to the second carrier group_1 of FIG. 56,using e^(j×F21) as the phase change value yp(i). Note that F21 isassumed to be a real number. For example, F21 is 0 (radians)≤F21<2×π(radians).

Assume that in the phase changer 305B, phase change is executed onsymbols belonging to the third carrier group_1 of FIG. 56, usinge^(j×F31) as the phase change value yp(i). Note that F31 is assumed tobe a real number. For example, F31 is 0 (radians)≤F31<2×π (radians).

Assume that in the phase changer 305B, phase change is executed onsymbols belonging to the fourth carrier group_1 of FIG. 56, usinge^(j×F41) as the phase change value yp(i). Note that F41 is assumed tobe a real number. For example, F41 is 0 (radians)≤F41<2×π (radians).

Assume that in the phase changer 305B, phase change is executed onsymbols belonging to the fifth carrier group_1 of FIG. 56, usinge^(j×F51) as the phase change value yp(i). Note that F51 is assumed tobe a real number. For example, F51 is 0 (radians)≤F51<2×π (radians).

As a first example, there is a method in which “F11≠F21, and F11≠F31,and F11≠F41, and F11≠F51, and F21≠F31, and F21≠F41, and F21≠F51, andF31≠F41, and F31≠F51, and F41≠F51” holds. When generalized, the methodis one in which “x is an integer equal to 1 or greater, y is an integerequal to 1 or greater, x≠y holds, and for all x and y satisfying theseconditions, Fx1≠Fy1 holds”.

As a second example, there is a method in which “F11≠F21, or F11≠F31, orF11≠F41, or F11≠F51, or F21≠F31, or F21≠F41, or F21≠F51, or F31≠F41, orF31≠F51, or F41≠F51” holds. When generalized, the method is one in which“there exists a set of x, y such that x is an integer equal to 1 orgreater, y is an integer equal to 1 or greater, x≠y holds, and Fx1≠Fy1holds”.

Also, assume that in the phase changer 3801A, phase change is executedon symbols belonging to the first carrier group_1 of FIG. 56, usinge^(j×G11) as the phase change value Vp(i). Note that G11 is assumed tobe a real number. For example, G11 is 0 (radians)≤G11<2×π (radians).

Additionally, assume that in the phase changer 3801A, phase change isexecuted on symbols belonging to the second carrier group_1 of FIG. 56,using e^(j×G21) as the phase change value Vp(i). Note that G21 isassumed to be a real number. For example, G21 is 0 (radians)≤G21<2×π(radians).

Assume that in the phase changer 3801A, phase change is executed onsymbols belonging to the third carrier group_1 of FIG. 56, usinge^(j×G31) as the phase change value Vp(i). Note that G31 is assumed tobe a real number. For example, G31 is 0 (radians)≤G31<2×π (radians).

Assume that in the phase changer 3801A, phase change is executed onsymbols belonging to the fourth carrier group_1 of FIG. 56, usinge^(j×G41) as the phase change value Vp(i). Note that G41 is assumed tobe a real number. For example, G41 is 0 (radians)≤G41<2×π (radians).

Assume that in the phase changer 3801A, phase change is executed onsymbols belonging to the fifth carrier group_1 of FIG. 56, usinge^(j×G51) as the phase change value Vp(i). Note that G51 is assumed tobe a real number. For example, G51 is 0 (radians)≤G51<2×π (radians).

For example, as a first example, there is a method in which “G11≠G21,and G11≠G31, and G11≠G41, and G11≠G51, and G21≠G31, and G21≠G41, andG21≠G51, and G31≠G41, and G31≠G51, and G41≠G51” holds. When generalized,the method is one in which “x is an integer equal to 1 or greater, y isan integer equal to 1 or greater, x≠y holds, and for all x and ysatisfying these conditions, Gx1≠Gy1 holds”.

As a second example, there is a method in which “G11≠G21, or G11≠G31, orG11≠G41, or G11≠G51, or G21≠G31, or G21≠G41, or G21≠G51, or G31≠G41, orG31≠G51, or G41≠G51” holds. When generalized, the method is one in which“there exists a set of x, y such that x is an integer equal to 1 orgreater, y is an integer equal to 1 or greater, x≠y holds, and Gx1≠Gy1holds”.

Also, assume that in the phase changer 3801B, phase change is executedon symbols belonging to the first carrier group_1 of FIG. 56, usinge^(j×H11) as the phase change value vp(i). Note that H11 is assumed tobe a real number. For example, H11 is 0 (radians)≤H11<2×π (radians).

Additionally, assume that in the phase changer 3801B, phase change isexecuted on symbols belonging to the second carrier group_1 of FIG. 56,using e^(j×H21) as the phase change value vp(i). Note that H21 isassumed to be a real number. For example, H21 is 0 (radians)≤H21<2×π(radians).

Assume that in the phase changer 3801B, phase change is executed onsymbols belonging to the third carrier group_1 of FIG. 56, usinge^(j×H31) as the phase change value vp(i). Note that H31 is assumed tobe a real number. For example, H31 is 0 (radians)≤H31<2×π (radians).

Assume that in the phase changer 3801B, phase change is executed onsymbols belonging to the fourth carrier group_1 of FIG. 56, usinge^(j×H41) as the phase change value vp(i). Note that H41 is assumed tobe a real number. For example, H41 is 0 (radians)≤H41<2×π (radians).

Assume that in the phase changer 3801B, phase change is executed onsymbols belonging to the fifth carrier group_1 of FIG. 56, usinge^(j×H51) as the phase change value vp(i). Note that H51 is assumed tobe a real number. For example, H51 is 0 (radians)≤H51<2×π (radians).

As a first example, there is a method in which “H11≠H21, and H11≠H31,and H11≠H41, and H11≠H51, and H21≠H31, and H21≠H41, and H21≠H51, andH31≠H41, and H31≠H51, and H41≠H51” holds. When generalized, the methodis one in which “x is an integer equal to 1 or greater, y is an integerequal to 1 or greater, x≠y holds, and for all x and y satisfying theseconditions, Hx1≠Hy1 holds”.

As a second example, there is a method in which “H11≠H21, or H11≠H31, orH11≠H41, or H11≠H51, or H21≠H31, or H21≠H41, or H21≠H51, or H31≠H41, orH31≠H51, or H41≠H51” holds. When generalized, the method is one in which“there exists a set of x, y such that x is an integer equal to 1 orgreater, y is an integer equal to 1 or greater, x≠y holds, and Hx1≠Hy1holds”.

Assume that in the phase changer 305A, phase change is executed onsymbols belonging to the first carrier group_2 of FIG. 56, usinge^(j×E12) as the phase change value Yp(i). Note that E12 is assumed tobe a real number. For example, E12 is 0 (radians)≤E12<2×π (radians).

Additionally, assume that in the phase changer 305A, phase change isexecuted on symbols belonging to the second carrier group_2 of FIG. 56,using e^(j×E22) as the phase change value Yp(i). Note that E22 isassumed to be a real number. For example, E22 is 0 (radians)≤E22<2×π(radians).

Assume that in the phase changer 305A, phase change is executed onsymbols belonging to the third carrier group_2 of FIG. 56, usinge^(j×E32) as the phase change value Yp(i). Note that E32 is assumed tobe a real number. For example, E32 is 0 (radians)≤E32<2×π (radians).

Assume that in the phase changer 305A, phase change is executed onsymbols belonging to the fourth carrier group_2 of FIG. 56, usinge^(j×E42) as the phase change value Yp(i). Note that E42 is assumed tobe a real number. For example, E42 is 0 (radians)≤E42<2×π (radians).

Assume that in the phase changer 305A, phase change is executed onsymbols belonging to the fifth carrier group_2 of FIG. 56, usinge^(j×E52) as the phase change value Yp(i). Note that E52 is assumed tobe a real number. For example, E52 is 0 (radians)≤E52<2×π (radians).

As a first example, there is a method in which “E12≠E22, and E12≠E32,and E12≠E42, and E12≠E52, and E22≠E32, and E22≠E42, and E22≠E52, andE32≠E42, and E32≠E52, and E42≠E52” holds. When generalized, the methodis one in which “x is an integer equal to 1 or greater, y is an integerequal to 1 or greater, x≠y holds, and for all x and y satisfying theseconditions, Ex2≠Ey2 holds”.

As a second example, there is a method in which “E12≠E22, or E12≠E32, orE12≠E42, or E12≠E52, or E22≠E32, or E22≠E42, or E22≠E52, or E32≠E42, orE32≠E52, or E42≠E52” holds. When generalized, the method is one in which“there exists a set of x, y such that x is an integer equal to 1 orgreater, y is an integer equal to 1 or greater, x≠y holds, and Ex2≠Ey2holds”.

Also, assume that in the phase changer 305B, phase change is executed onsymbols belonging to the first carrier group_2 of FIG. 56, usinge^(j×F12) as the phase change value yp(i). Note that F12 is assumed tobe a real number. For example, F12 is 0 (radians)≤F12<2×π (radians).

Additionally, assume that in the phase changer 305B, phase change isexecuted on symbols belonging to the second carrier group_2 of FIG. 56,using e^(j×F22) as the phase change value yp(i). Note that F22 isassumed to be a real number. For example, F22 is 0 (radians)≤F22<2×π(radians).

Assume that in the phase changer 305B, phase change is executed onsymbols belonging to the third carrier group_2 of FIG. 56, usinge^(j×F32) as the phase change value yp(i). Note that F32 is assumed tobe a real number. For example, F32 is 0 (radians)≤F32<2×π (radians).

Assume that in the phase changer 305B, phase change is executed onsymbols belonging to the fourth carrier group_2 of FIG. 56, usinge^(j×F42) as the phase change value yp(i). Note that F42 is assumed tobe a real number. For example, F42 is 0 (radians)≤F42<2×π (radians).

Assume that in the phase changer 305B, phase change is executed onsymbols belonging to the fifth carrier group_2 of FIG. 56, usinge^(j×F52) as the phase change value yp(i). Note that F52 is assumed tobe a real number. For example, F52 is 0 (radians)≤F52<2×π (radians).

As a first example, there is a method in which “F12≠F22, and F12≠F32,and F12≠F42, and F12≠F52, and F22≠F32, and F22≠F42, and F22≠F52, andF32≠F42, and F32≠F52, and F42≠F52” holds. When generalized, the methodis one in which “x is an integer equal to 1 or greater, y is an integerequal to 1 or greater, x≠y holds, and for all x and y satisfying theseconditions, Fx2≠Fy2 holds”.

As a second example, there is a method in which “F12≠F22, or F12≠F32, orF12≠F42, or F12≠F52, or F22≠F32, or F22≠F42, or F22≠F52, or F32≠F42, orF32≠F52, or F42≠F52” holds. When generalized, the method is one in which“there exists a set of x, y such that x is an integer equal to 1 orgreater, y is an integer equal to 1 or greater, x≠y holds, and Fx2≠Fy2holds”.

Also, assume that in the phase changer 3801A, phase change is executedon symbols belonging to the first carrier group_2 of FIG. 56, usinge^(j×G12) as the phase change value Vp(i). Note that G12 is assumed tobe a real number. For example, G12 is 0 (radians)≤G12<2×π (radians).

Additionally, assume that in the phase changer 3801A, phase change isexecuted on symbols belonging to the second carrier group_2 of FIG. 56,using e^(j×G22) as the phase change value Vp(i). Note that G22 isassumed to be a real number. For example, G22 is 0 (radians)≤G22<2×π(radians).

Assume that in the phase changer 3801A, phase change is executed onsymbols belonging to the third carrier group_2 of FIG. 56, usinge^(j×G32) as the phase change value Vp(i). Note that G32 is assumed tobe a real number. For example, G32 is 0 (radians)≤G32<2×π (radians).

Assume that in the phase changer 3801A, phase change is executed onsymbols belonging to the fourth carrier group_2 of FIG. 56, usinge^(j×G42) as the phase change value Vp(i). Note that G42 is assumed tobe a real number. For example, G42 is 0 (radians)≤G42<2×π (radians).

Assume that in the phase changer 3801A, phase change is executed onsymbols belonging to the fifth carrier group_2 of FIG. 56, usinge^(j×G52) as the phase change value Vp(i). Note that G52 is assumed tobe a real number. For example, G52 is 0 (radians)≤G52<2×π (radians).

As a first example, there is a method in which “G12≠G22, and G12≠G32,and G12≠G42, and G12≠G52, and G22≠G32, and G22≠G42, and G22≠G52, andG32≠G42, and G32≠G52, and G42≠G52” holds. When generalized, the methodis one in which “x is an integer equal to 1 or greater, y is an integerequal to 1 or greater, x≠y holds, and for all x and y satisfying theseconditions, Gx2≠Gy2 holds”.

As a second example, there is a method in which “G12≠G22, or G12≠G32, orG12≠G42, or G12≠G52, or G22≠G32, or G22≠G42, or G22≠G52, or G32≠G42, orG32≠G52, or G42≠G52” holds. When generalized, the method is one in which“there exists a set of x, y such that x is an integer equal to 1 orgreater, y is an integer equal to 1 or greater, x≠y holds, and Gx2≠Gy2holds”.

Also, assume that in the phase changer 3801B, phase change is executedon symbols belonging to the first carrier group_2 of FIG. 56, usinge^(j×H12) as the phase change value vp(i). Note that H12 is assumed tobe a real number. For example, H12 is 0 (radians)≤H12<2×π (radians).

Additionally, assume that in the phase changer 3801B, phase change isexecuted on symbols belonging to the second carrier group_2 of FIG. 56,using e^(j×H22) as the phase change value vp(i). Note that H22 isassumed to be a real number. For example, H22 is 0 (radians)≤H22<2×π(radians).

Assume that in the phase changer 3801B, phase change is executed onsymbols belonging to the third carrier group_2 of FIG. 56, usinge^(j×H32) as the phase change value vp(i). Note that H32 is assumed tobe a real number. For example, H32 is 0 (radians)≤H32<2×π (radians).

Assume that in the phase changer 3801B, phase change is executed onsymbols belonging to the fourth carrier group_2 of FIG. 56, usinge^(j×H42) as the phase change value vp(i). Note that H42 is assumed tobe a real number. For example, H42 is 0 (radians)≤H42<2×π (radians).

Assume that in the phase changer 3801B, phase change is executed onsymbols belonging to the fifth carrier group_2 of FIG. 56, usinge^(j×H52) as the phase change value vp(i). Note that H52 is assumed tobe a real number. For example, H52 is 0 (radians)≤H52<2×π (radians).

As a first example, there is a method in which “H12≠H22, and H12≠H32,and H12≠H42, and H12≠H52, and H22≠H32, and H22≠H42, and H22≠H52, andH32≠H42, and H32≠H52, and H42≠H52” holds. When generalized, the methodis one in which “x is an integer equal to 1 or greater, y is an integerequal to 1 or greater, x≠y holds, and for all x and y satisfying theseconditions, Hx2≠Hy2 holds”.

As a second example, there is a method in which “H12≠H22, or H12≠H32, orH12≠H42, or H12≠H52, or H22≠H32, or H22≠H42, or H22≠H52, or H32≠H42, orH32≠H52, or H42≠H52” holds. When generalized, the method is one in which“there exists a set of x, y such that x is an integer equal to 1 orgreater, y is an integer equal to 1 or greater, x≠y holds, and Hx2≠Hy2holds”.

Assume that in the phase changer 305A, phase change is executed onsymbols belonging to the first carrier group_3 of FIG. 56, usinge^(j×E13) as the phase change value Yp(i). Note that E13 is assumed tobe a real number. For example, E13 is 0 (radians)≤E13<2×π (radians).

Assume that in the phase changer 305A, phase change is executed onsymbols belonging to the first carrier group_4 of FIG. 56, usinge^(j×E14) as the phase change value Yp(i). Note that E14 is assumed tobe a real number. For example, E14 is 0 (radians)≤E14<2×π (radians).

Additionally, assume that in the phase changer 305A, phase change isexecuted on symbols belonging to the second carrier group_4 of FIG. 56,using e^(j×E24) as the phase change value Yp(i). Note that E24 isassumed to be a real number. For example, E24 is 0 (radians)≤E24<2×π(radians).

Assume that in the phase changer 305A, phase change is executed onsymbols belonging to the third carrier group_4 of FIG. 56, usinge^(j×E34) as the phase change value Yp(i). Note that E34 is assumed tobe a real number. For example, E34 is 0 (radians)≤E34<2×π (radians).

As a first example, there is a method in which “E14≠E24, and E14≠E34,and E24≠E34” holds. When generalized, the method is one in which “x isan integer equal to 1 or greater, y is an integer equal to 1 or greater,x≠y holds, and for all x and y satisfying these conditions, Ex4≠Ey4holds”.

As a second example, there is a method in which “E14≠E24, or E14≠E34, orE24≠E34” holds. When generalized, the method is one in which “thereexists a set of x, y such that x is an integer equal to 1 or greater, yis an integer equal to 1 or greater, x≠y holds, and Ex4≠Ey4 holds”.

Also, assume that in the phase changer 305B, phase change is executed onsymbols belonging to the first carrier group_4 of FIG. 56, usinge^(j×F14) as the phase change value yp(i). Note that F14 is assumed tobe a real number. For example, F14 is 0 (radians)≤F14<2×π (radians).

Additionally, assume that in the phase changer 305B, phase change isexecuted on symbols belonging to the second carrier group_4 of FIG. 56,using e^(j×F24) as the phase change value yp(i). Note that F24 isassumed to be a real number. For example, F24 is 0 (radians)≤F24<2×π(radians).

Assume that in the phase changer 305B, phase change is executed onsymbols belonging to the third carrier group_4 of FIG. 56, usinge^(j×F34) as the phase change value yp(i). Note that F34 is assumed tobe a real number. For example, F34 is 0 (radians)≤F34<2×π (radians).

As a first example, there is a method in which “F14≠F24, and F14≠F34,and F24≠F34” holds. When generalized, the method is one in which “x isan integer equal to 1 or greater, y is an integer equal to 1 or greater,x≠y holds, and for all x and y satisfying these conditions, Fx4≠Fy4holds”.

As a second example, there is a method in which “F14≠F24, or F14≠F34, orF24≠F34” holds. When generalized, the method is one in which “thereexists a set of x, y such that x is an integer equal to 1 or greater, yis an integer equal to 1 or greater, x≠y holds, and Fx4≠Fy4 holds”.

Also, assume that in the phase changer 3801A, phase change is executedon symbols belonging to the first carrier group_4 of FIG. 56, usinge^(j×G14) as the phase change value Vp(i). Note that G14 is assumed tobe a real number. For example, G14 is 0 (radians)≤G14<2×π (radians).

Additionally, assume that in the phase changer 3801A, phase change isexecuted on symbols belonging to the second carrier group_4 of FIG. 56,using e^(j×G24) as the phase change value Vp(i). Note that G24 isassumed to be a real number. For example, G24 is 0 (radians)≤G24<2×π(radians).

Assume that in the phase changer 3801A, phase change is executed onsymbols belonging to the third carrier group_4 of FIG. 56, usinge^(j×G34) as the phase change value Vp(i). Note that G34 is assumed tobe a real number. For example, G34 is 0 (radians)≤G34<2×π (radians).

For example, as a first example, there is a method in which “G14≠G24,and G14≠G34, and G24≠G34” holds. When generalized, the method is one inwhich “x is an integer equal to 1 or greater, y is an integer equal to 1or greater, x≠y holds, and for all x and y satisfying these conditions,Gx4≠Gy4 holds”.

As a first example, there is a method in which “G14≠G24, or G14≠G34, orG24≠G34” holds. When generalized, the method is one in which “thereexists a set of x, y such that x is an integer equal to 1 or greater, yis an integer equal to 1 or greater, x≠y holds, and Gx4≠Gy4 holds”.

Also, assume that in the phase changer 3801B, phase change is executedon symbols belonging to the first carrier group_4 of FIG. 56, usinge^(j×H14) as the phase change value vp(i). Note that H14 is assumed tobe a real number. For example, H14 is 0 (radians)≤H14<2×π (radians).

Additionally, assume that in the phase changer 3801B, phase change isexecuted on symbols belonging to the second carrier group_4 of FIG. 56,using e^(j×H24) as the phase change value vp(i). Note that H24 isassumed to be a real number. For example, H24 is 0 (radians)≤H24<2×π(radians).

Assume that in the phase changer 3801B, phase change is executed onsymbols belonging to the third carrier group_4 of FIG. 56, usinge^(j×H34) as the phase change value vp(i). Note that H34 is assumed tobe a real number. For example, H34 is 0 (radians)≤H34<2×π (radians).

As a first example, there is a method in which “H14≠F24, and H14≠H34,and H24≠H34” holds. When generalized, the method is one in which “x isan integer equal to 1 or greater, y is an integer equal to 1 or greater,x≠y holds, and for all x and y satisfying these conditions, Hx4≠Hy4holds”.

As a second example, there is a method in which “H14≠F24, or H14≠H34, orH24≠H34” holds. When generalized, the method is one in which “thereexists a set of x, y such that x is an integer equal to 1 or greater, yis an integer equal to 1 or greater, x≠y holds, and Hx4≠Hy4 holds”.

At this time, characteristics like the following may be included.

-   -   Like the “segment from time $1 to time $3” and “from time $4 to        time $9”, when the method of dividing frequencies is the same        (the frequency used by the first carrier group_1 and the        frequency used by the first carrier group_2 are the same, and        the frequency used by the second carrier group_1 and the        frequency used by the second carrier group_2 are the same, and        the frequency used by the third carrier group_1 and the        frequency used by the third carrier group_2 are the same, and        the frequency used by the fourth carrier group_1 and the        frequency used by the fourth carrier group_2 are the same, and        the frequency used by the fifth carrier group_1 and the        frequency used by the fifth carrier group_2 are the same), the        phase change value used by the Xth carrier group_1 (where X is        1, 2, 3, 4, 5) in the “segment from time $1 to time $3” and the        phase change value used by the Xth carrier group_2 in the        “segment from time $4 to time $9” may be the same or different.

For example, E11=E12 may hold, or E11≠E12 may hold. E21=E22 may hold, orE21≠E22 may hold. E31=E32 may hold, or E31≠E32 may hold. E41=E42 mayhold, or E41≠E42 may hold. E51=E52 may hold, or E51≠E52 may hold.

Also, F11=F12 may hold, or F11≠F12 may hold. F21=F22 may hold, orF21≠F22 may hold. F31=F32 may hold, or F31≠F32 may hold. F41=F42 mayhold, or F41≠F42 may hold. F51=F52 may hold, or F51≠F52 may hold.

G11=G12 may hold, or G11≠G12 may hold. G21=G22 may hold, or G21≠G22 mayhold. G31=G32 may hold, or G31≠G32 may hold. G41=G42 may hold, orG41≠G42 may hold. G51=G52 may hold, or G51≠G52 may hold.

H11=H12 may hold, or H11≠H12 may hold. H21=H22 may hold, or H21≠H22 mayhold. H31=H32 may hold, or H31≠H32 may hold. H41=H42 may hold, orH41≠H42 may hold. H51=H52 may hold, or H51≠H52 may hold.

-   -   The method of dividing frequency may also be changed together        with time. For example, “from time $1 to time $3” in FIG. 56,        the frequency is divided into 5 from carrier #1 to carrier #25,        and five carrier groups are generated. Subsequently, “from time        $10 to time $11”, a single carrier group containing carrier #1        to carrier #25 is generated. Also, “from time $12 to time $14”,        the frequency is divided into 3 from carrier #1 to carrier #25,        and three carrier groups are generated.

Note that the method of dividing frequency is not limited to the methodin FIG. 56. The frequencies allocated to a certain user may be treatedas one carrier group, or two or more carrier groups may be generated.Also, it is sufficient for the number of carriers included in a carriergroup to be 1 or more.

The description described above using FIG. 56 states that “to transmitdata to a certain terminal (certain user) (terminal #p), the basestation or AP uses from carrier #1 to carrier #25, from time $1 to time$14”, but the base station or AP may also allocate from carrier #1 tocarrier #25, from time $1 to time $14 to transmit data to multipleterminals (multiple users). Hereinafter, this point will be described.Note that the settings with respect to each carrier group of the phasechange value Yp(i) used by the phase changer 305A, the phase changevalue yp(i) used by the phase changer 305B, the phase change value Vp(i)used by the phase changer 3801A, and the phase change value vp(i) usedby the phase changer 3801B in FIGS. 3, 4, 26, 38, 39, 40, 41, 42, 43,44, 45, 46, 47, 48, 49, and the like are as described above, and thus adescription is omitted.

As a first example, in FIG. 56, terminal allocation (user allocation)may be executed using time division.

For example, assume that the base station or AP uses “from time $1 totime $3” to transmit data to the terminal (user) p1 (that is, p=p1).Additionally, assume that the base station or AP uses “from time $4 totime $9” to transmit data to the terminal (user) p2 (that is, p=p2).Assume that the base station or AP uses “from time $10 to time $11” totransmit data to the terminal (user) p3 (that is, p=p3). Assume that thebase station or AP uses “from time $12 to time $14” to transmit data tothe terminal (user) p4 (that is, p=p4).

As a second example, in FIG. 56, terminal allocation (user allocation)may be executed using frequency division.

For example, assume that the base station or AP uses the first carriergroup_1 and the second carrier group_1 to transmit data to the terminal(user) p1 (that is, p=p1). Additionally, assume that the base station orAP uses the third carrier group_1, the fourth carrier group_1, and thefifth carrier group_1 to transmit data to the terminal (user) p2 (thatis, p=p2).

As a third example, in FIG. 56, terminal allocation (user allocation)may be executed using combined time and frequency division.

For example, assume that the base station or AP uses the first carriergroup_1, the first carrier group_2, the second carrier group_1, and thesecond carrier group_2 to transmit data to the terminal (user) p1 (thatis, p=p1). Additionally, assume that the base station or AP uses thethird carrier group_1, the fourth carrier group_1, and the fifth carriergroup_1 to transmit data to the terminal (user) p2 (that is, p=p2).Assume that the base station or AP uses the third carrier group_2 andthe fourth carrier group_2 to transmit data to the terminal (user) p3(that is, p=p3). Assume that the base station or AP uses the fifthcarrier group_2 to transmit data to the terminal (user) p4 (that is,p=p4). Assume that the base station or AP uses the first carrier group_3to transmit data to the terminal (user) p5 (that is, p=p5). Assume thatthe base station or AP uses the first carrier group_4 to transmit datato the terminal (user) p6 (that is, p=p6). Assume that the base stationor AP uses the second carrier group_4 and the third carrier group_4 totransmit data to the terminal (user) p7 (that is, p=p7).

Note that in the description described above, the method of configuringthe carrier groups is not limited to FIG. 56. For example, as long asthere are one or more carriers included in a carrier group, the carriergroups may be configured in any way. Also, the intervals of timeincluded in a carrier group are not limited to the configuration in FIG.56. Also, the frequency division method, the time division method, andthe combined time and frequency division method for user allocation isnot limited to the examples described above, and it is possible to carryout an embodiment by executing any kind of division.

According to examples like the above, in the phase changer 305B, thephase changer 305A, the phase changer 3801B, and the phase changer 3801Ain FIGS. 3, 4, 26, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, andthe like described in Embodiment 1 to Embodiment 11, Supplement 1 toSupplement 4, and the like, by “changing the phase periodically orregularly”, the advantageous effects described in Embodiment 1 toEmbodiment 11, Supplement 1 to Supplement 4, and the like may beobtained.

Note that in FIGS. 3, 4, 26, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48,49, and the like, the configuration from the inserter 307A and theinserter 307B may also be the configuration of FIG. 57. FIG. 57 is adiagram illustrating an example of a configuration in which phasechangers are added. In FIG. 57, the characteristic point is that thephase changer 309A has been inserted. The operation of the phase changer309A executes signal processing for phase change or CDD (CSD) similarlyto the phase changer 309B.

Embodiment 13

In Embodiment 1 to Embodiment 11, Supplement 1 to Supplement 4, and thelike, if both “the phase changer 305B, the phase changer 305A, the phasechanger 3801B, and the phase changer 3801A in FIGS. 3, 4, 26, 38, 39,40, 41, 42, 43, 44, 45, 46, 47, 48, 49, and the like” and thecomputations in the weight combiner 303 are considered as a whole, suchas by referencing Formula (37), Formula (42), Formula (43), Formula(45), Formula (47), and Formula (48), for example, the precoding matrixcorresponds to switching according to i.

Also, in the weight combiner 303, in the case of using Formula (21),Formula (22), Formula (23), Formula (24), Formula (25), Formula (26),Formula (27), and Formula (28), for example, the precoding matrixcorresponds to switching according to i.

If considered with reference to Formula (37), Formula (42), Formula(43), Formula (45), Formula (47), and Formula (48), when the precodingmatrix is switched by i, Formula (52) holds. Note that i is taken to bethe symbol number. For example, i is an integer equal to 0 or greater.

$\begin{matrix}{\begin{pmatrix}{{zp}\; 1(i)} \\{{zp}\; 2(i)}\end{pmatrix} = {{{{Fp}(i)}\begin{pmatrix}{{sp}\; 1(i)} \\{{sp}\; 2(i)}\end{pmatrix}} = {\begin{pmatrix}{{ap}(i)} & {{bp}(i)} \\{{cp}(i)} & {{dp}(i)}\end{pmatrix}\begin{pmatrix}{{sp}\; 1(i)} \\{{sp}\; 2(i)}\end{pmatrix}}}} & (52)\end{matrix}$Note that in Formula (52), zp1(i) is the first phase-changed signal,zp2(i) is the second phase-changed signal, sp1(i) is the user #p mappedsignal 301A, and sp2(i) is the user #p mapped signal 301B. Fp(i) is amatrix used in weight combining, that is, a precoding matrix. Theprecoding matrix may be treated as a function of i. For example, theoperation may be one of switching the precoding matrix periodically orregularly. However, in the present embodiment, zp1(i) is called thefirst precoded signal, and zp2(i) is called the second precoded signal.Note that from Formula (52), Formula (53) holds.

$\begin{matrix}{{{Fp}(i)} = \begin{pmatrix}{{ap}(i)} & {{bp}(i)} \\{{cp}(i)} & {{dp}(i)}\end{pmatrix}} & (53)\end{matrix}$Note that in Formula (53), ap(i) may be defined as a complex number.Thus, ap(i) may also be a real number. Also, bp(i) may be defined as acomplex number. Thus, bp(i) may also be a real number. Also, cp(i) maybe defined as a complex number. Thus, cp(i) may also be a real number.Also, dp(i) may be defined as a complex number. Thus, dp(i) may also bea real number.

Since this is similar to the description of Formula (37), Formula (42),Formula (43), Formula (45), Formula (47), and Formula (48), zp1(i)corresponds to 103_p_1 in FIG. 1, and zp2(i) corresponds to 103_p_2 inFIG. 1. Alternatively, zp1(i) corresponds to 103_p_1 in FIG. 52, andzp2(i) corresponds to 103_p_2 in FIG. 52. Note that zp1(i) and zp2(i)are transmitted using identical frequencies and identical times.

FIG. 58 is a diagram illustrating a first exemplary configuration of theuser #p signal processor 102_p of FIGS. 1 and 52 including thecomputation (Formula (52)) described above. In FIG. 58, parts whichoperate similarly to FIG. 3 and the like are denoted with the samenumbers, and a detailed description is omitted.

The computation of Formula (52) is executed by a weight combiner A401 inFIG. 58.

FIG. 59 is a diagram illustrating a second exemplary configuration ofthe user #p signal processor 102_p of FIGS. 1 and 52 including thecomputation (Formula (52)) described above. In FIG. 59, parts whichoperate similarly to FIG. 3 and the like are denoted with the samenumbers, and a detailed description is omitted.

Similarly to FIG. 58, the computation of Formula (52) is executed by theweight combiner A401 in FIG. 59. The characteristic point is that theweight combiner A401 executes the precoding process while switching theprecoding matrix regularly or periodically, for example. In FIG. 59, thepoint of difference from FIG. 58 is that the phase changer 309A has beeninserted. Note that the detailed operation of precoding switching willbe described later. The operation of the phase changer 309A executessignal processing for phase change or CDD (CSD) similarly to the phasechanger 309B.

Although not illustrated in FIGS. 58 and 59, each of the pilot symbolsignal (pa(t)) (351A), the pilot symbol signal (pb(t)) (351B), thepreamble signal 352, and the control information symbol signal 353 mayalso be a signal subjected to processing such as phase change.

Additionally, zp1(i) and zp2(i) are processed as illustrated in FIG. 1or FIG. 52. This point has been described in the foregoing embodiments.

Meanwhile, in Embodiment 1 to Embodiment 11, Supplement 1 to Supplement4, and the like, the phase changer 305B, the phase changer 305A, thephase changer 3801B, and the phase changer 3801A in FIGS. 3, 4, 26, 38,39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, and the like are describedusing Formula (2), Formula (44), and the like, for example; while inaddition, it is noted that the values of the phase change values do nothave to be based on these formulas, and also that “it is sufficient tochange the phase periodically or regularly”. Consequently, for theprecoding matrix indicated by Formula (53) in Formula (52), “it issufficient to change the precoding matrix periodically or regularly”.Hereinafter, an example of changing the precoding matrix periodically orregularly will be described.

For example, like in FIG. 55, consider a first carrier group includingcarrier #1 to carrier #5, a second carrier group including carrier #6 tocarrier #10, a third carrier group including carrier #11 to carrier #15,a fourth carrier group including carrier #16 to carrier #20, and a fifthcarrier group including carrier #21 to carrier #25. Assume that, totransmit data to a certain terminal (certain user) (terminal #p), thebase station or AP uses the first carrier group, the second carriergroup, the third carrier group, the fourth carrier group, and the fifthcarrier group.

At this time, assume that precoding is performed on the symbol (set)(sp1(i) and sp2(i)) belonging to the first carrier group in FIG. 55,using U1 as the precoding matrix Fp(i) in Formula (52) and Formula (53).

Additionally, assume that precoding is performed on the symbol (set)(sp1(i) and sp2(i)) belonging to the second carrier group in FIG. 55,using U2 as the precoding matrix Fp(i) in Formula (52) and Formula (53).

Assume that precoding is performed on the symbol (set) (sp1(i) andsp2(i)) belonging to the third carrier group in FIG. 55, using U3 as theprecoding matrix Fp(i) in Formula (52) and Formula (53).

Assume that precoding is performed on the symbol (set) (sp1(i) andsp2(i)) belonging to the fourth carrier group in FIG. 55, using U4 asthe precoding matrix Fp(i) in Formula (52) and Formula (53).

Assume that precoding is performed on the symbol (set) (sp1(i) andsp2(i)) belonging to the fifth carrier group in FIG. 55, using U5 as theprecoding matrix Fp(i) in Formula (52) and Formula (53).

As a first example, there is a method in which “U1≠U2, and U1≠U3, andU1≠U4, and U1≠U5, and U2≠U3, and U2≠U4, and U2≠U5, and U3≠U4, and U3≠U5,and U4≠U5” holds. When generalized, the method is one in which “x is aninteger equal to 1 or greater, y is an integer equal to 1 or greater,x≠y holds, and for all x and y satisfying these conditions, Ux≠Uyholds”.

As a second example, there is a method in which “U1≠U2, or U1≠U3, orU1≠U4, or U1≠U5, or U2≠U3, or U2≠U4, or U2≠U5, or U3≠U4, or U3≠U5, orU4≠U5” holds. When generalized, the method is one in which “there existsa set of x, y such that x is an integer equal to 1 or greater, y is aninteger equal to 1 or greater, x≠y holds, and Ux≠Uy holds”.

Note that although the first carrier group to the fifth carrier groupexist in FIG. 55, the number of existing carrier groups is not limitedto 5, and it is possible to carry out the embodiment similarly insofaras there are 2 or more carrier groups. Also, the carrier groups may beset to 1. For example, one or more carrier groups may be configured toexist, on the basis of communication conditions, feedback informationfrom a terminal, and the like. When the carrier group is 1, the changingof the precoding matrix is not executed. Like the example in FIG. 55,each carrier group may also be set to a fixed number of values.

Also, a configuration is taken in which all of the first carrier group,the second carrier group, the third carrier group, the fourth carriergroup, and the fifth carrier group are provided with five carriers, butthe configuration is not limited thereto. Consequently, it is sufficientfor a carrier group to be provided with one or more carriers.Additionally, different carrier groups may have the same or differentnumbers of provided carriers. For example, in FIG. 55, the number ofcarriers provided in the first carrier group is 5, and the number ofcarriers provided in the second carrier group is also 5 (the same). As adifferent example, the number of carriers provided in the first carriergroup of FIG. 55 may be set to 5, while the number of carriers providedin the second carrier group may be set to a different number such as 10.

Additionally, the matrices U1, U2, U3, U4, and U5 are conceivablyexpressed by the matrix on the left side of Formula (5), the matrix onthe left side of Formula (6), the matrix on the left side of Formula(7), the matrix on the left side of Formula (8), the matrix on the leftside of Formula (9), the matrix on the left side of Formula (10), thematrix on the left side of Formula (11), the matrix on the left side ofFormula (12), the matrix on the left side of Formula (13), the matrix onthe left side of Formula (14), the matrix on the left side of Formula(15), the matrix on the left side of Formula (16), the matrix on theleft side of Formula (17), the matrix on the left side of Formula (18),the matrix on the left side of Formula (19), the matrix on the left sideof Formula (20), the matrix on the left side of Formula (21), the matrixon the left side of Formula (22), the matrix on the left side of Formula(23), the matrix on the left side of Formula (24), the matrix on theleft side of Formula (25), the matrix on the left side of Formula (26),the matrix on the left side of Formula (27), the matrix on the left sideof Formula (28), the matrix on the left side of Formula (29), the matrixon the left side of Formula (30), the matrix on the left side of Formula(31), the matrix on the left side of Formula (32), the matrix on theleft side of Formula (33), the matrix on the left side of Formula (34),the matrix on the left side of Formula (35), the matrix on the left sideof Formula (36), and the like, for example, but the matrices are notlimited thereto.

In other words, the precoding matrix Fp(i) may be any kind of matrixsuch as the matrix on the left side of Formula (5), the matrix on theleft side of Formula (6), the matrix on the left side of Formula (7),the matrix on the left side of Formula (8), the matrix on the left sideof Formula (9), the matrix on the left side of Formula (10), the matrixon the left side of Formula (11), the matrix on the left side of Formula(12), the matrix on the left side of Formula (13), the matrix on theleft side of Formula (14), the matrix on the left side of Formula (15),the matrix on the left side of Formula (16), the matrix on the left sideof Formula (17), the matrix on the left side of Formula (18), the matrixon the left side of Formula (19), the matrix on the left side of Formula(20), the matrix on the left side of Formula (21), the matrix on theleft side of Formula (22), the matrix on the left side of Formula (23),the matrix on the left side of Formula (24), the matrix on the left sideof Formula (25), the matrix on the left side of Formula (26), the matrixon the left side of Formula (27), the matrix on the left side of Formula(28), the matrix on the left side of Formula (29), the matrix on theleft side of Formula (30), the matrix on the left side of Formula (31),the matrix on the left side of Formula (32), the matrix on the left sideof Formula (33), the matrix on the left side of Formula (34), the matrixon the left side of Formula (35), and the matrix on the left side ofFormula (36).

FIG. 56 illustrates a different example from FIG. 55 of carrier groupsof modulated signals transmitted by a base station or AP, takingfrequency (carrier) on the horizontal axis and time on the verticalaxis.

A first carrier group_1 includes from carrier #1 to carrier #5, and fromtime $1 to time $3. A second carrier group_1 includes from carrier #6 tocarrier #10, and from time $1 to time $3. A third carrier group_1includes from carrier #11 to carrier #15, and from time $1 to time $3. Afourth carrier group_1 includes from carrier #16 to carrier #20, andfrom time $1 to time $3. A fifth carrier group_1 includes from carrier#21 to carrier #25, and from time $1 to time $3.

A first carrier group_2 includes from carrier #1 to carrier #5, and fromtime $4 to time $9. A second carrier group_2 includes from carrier #6 tocarrier #10, and from time $4 to time $9. A third carrier group_2includes from carrier #11 to carrier #15, and from time $4 to time $9. Afourth carrier group_2 includes from carrier #16 to carrier #20, andfrom time $4 to time $9. A fifth carrier group_2 includes from carrier#21 to carrier #25, and from time $4 to time $9.

A first carrier group_3 includes from carrier #1 to carrier #25, andfrom time $10 to time $11.

A first carrier group_4 includes from carrier #1 to carrier #10, andfrom time $12 to time $14. A second carrier group_4 includes fromcarrier #11 to carrier #15, and from time $12 to time $14. A thirdcarrier group_4 includes from carrier #16 to carrier #25, and from time$12 to time $14.

In FIG. 56, assume that, to transmit data to a certain terminal (certainuser) (terminal #p), the base station or AP uses from carrier #1 tocarrier #25, from time $1 to time $14.

At this time, assume that precoding is performed on the symbol (set)(sp1(i) and sp2(i)) belonging to the first carrier group_1 in FIG. 56,using the matrix U11 as the precoding matrix Fp(i) in Formula (52) andFormula (53).

Additionally, assume that precoding is performed on the symbol (set)(sp1(i) and sp2(i)) belonging to the second carrier group_1 in FIG. 56,using the matrix U21 as the precoding matrix Fp(i) in Formula (52) andFormula (53).

Assume that precoding is performed on the symbol (set) (sp1(i) andsp2(i)) belonging to the third carrier group_1 in FIG. 56, using thematrix U31 as the precoding matrix Fp(i) in Formula (52) and Formula(53).

Assume that precoding is performed on the symbol (set) (sp1(i) andsp2(i)) belonging to the fourth carrier group_1 in FIG. 56, using thematrix U41 as the precoding matrix Fp(i) in Formula (52) and Formula(53).

Assume that precoding is performed on the symbol (set) (sp1(i) andsp2(i)) belonging to the fifth carrier group_1 in FIG. 56, using thematrix U51 as the precoding matrix Fp(i) in Formula (52) and Formula(53).

As a first example, there is a method in which “U11≠U21, and U11≠U31,and U11≠U41, and U11≠U51, and U21≠U31, and U21≠U41, and U21≠U51, andU31≠U41, and U31≠U51, and U41≠U51” holds. When generalized, the methodis one in which “x is an integer equal to 1 or greater, y is an integerequal to 1 or greater, x≠y holds, and for all x and y satisfying theseconditions, Ux1≠Uy1 holds”.

As a second example, there is a method in which “U11≠U21, or U11≠U31, orU11≠U41, or U11≠U51, or U21≠U31, or U21≠U41, or U21≠U51, or U31≠U41, orU31≠U51, or U41≠U51” holds. When generalized, the method is one in which“there exists a set of x, y such that x is an integer equal to 1 orgreater, y is an integer equal to 1 or greater, x≠y holds, and Ux1≠Uy1holds”.

Additionally, the matrices U11, U21, U31, U41, and U51 are conceivablyexpressed by the matrix on the left side of Formula (5), the matrix onthe left side of Formula (6), the matrix on the left side of Formula(7), the matrix on the left side of Formula (8), the matrix on the leftside of Formula (9), the matrix on the left side of Formula (10), thematrix on the left side of Formula (11), the matrix on the left side ofFormula (12), the matrix on the left side of Formula (13), the matrix onthe left side of Formula (14), the matrix on the left side of Formula(15), the matrix on the left side of Formula (16), the matrix on theleft side of Formula (17), the matrix on the left side of Formula (18),the matrix on the left side of Formula (19), the matrix on the left sideof Formula (20), the matrix on the left side of Formula (21), the matrixon the left side of Formula (22), the matrix on the left side of Formula(23), the matrix on the left side of Formula (24), the matrix on theleft side of Formula (25), the matrix on the left side of Formula (26),the matrix on the left side of Formula (27), the matrix on the left sideof Formula (28), the matrix on the left side of Formula (29), the matrixon the left side of Formula (30), the matrix on the left side of Formula(31), the matrix on the left side of Formula (32), the matrix on theleft side of Formula (33), the matrix on the left side of Formula (34),the matrix on the left side of Formula (35), the matrix on the left sideof Formula (36), and the like, for example, but the matrices are notlimited thereto.

In other words, the precoding matrix Fp(i) may be any kind of matrixsuch as the matrix on the left side of Formula (5), the matrix on theleft side of Formula (6), the matrix on the left side of Formula (7),the matrix on the left side of Formula (8), the matrix on the left sideof Formula (9), the matrix on the left side of Formula (10), the matrixon the left side of Formula (11), the matrix on the left side of Formula(12), the matrix on the left side of Formula (13), the matrix on theleft side of Formula (14), the matrix on the left side of Formula (15),the matrix on the left side of Formula (16), the matrix on the left sideof Formula (17), the matrix on the left side of Formula (18), the matrixon the left side of Formula (19), the matrix on the left side of Formula(20), the matrix on the left side of Formula (21), the matrix on theleft side of Formula (22), the matrix on the left side of Formula (23),the matrix on the left side of Formula (24), the matrix on the left sideof Formula (25), the matrix on the left side of Formula (26), the matrixon the left side of Formula (27), the matrix on the left side of Formula(28), the matrix on the left side of Formula (29), the matrix on theleft side of Formula (30), the matrix on the left side of Formula (31),the matrix on the left side of Formula (32), the matrix on the left sideof Formula (33), the matrix on the left side of Formula (34), the matrixon the left side of Formula (35), and the matrix on the left side ofFormula (36).

Also, assume that precoding is performed on the symbol (set) (sp1(i) andsp2(i)) belonging to the first carrier group_2 in FIG. 56, using thematrix U12 as the precoding matrix Fp(i) in Formula (52) and Formula(53).

Additionally, assume that precoding is performed on the symbol (set)(sp1(i) and sp2(i)) belonging to the second carrier group_2 in FIG. 56,using the matrix U22 as the precoding matrix Fp(i) in Formula (52) andFormula (53).

Assume that precoding is performed on the symbol (set) (sp1(i) andsp2(i)) belonging to the third carrier group_2 in FIG. 56, using thematrix U32 as the precoding matrix Fp(i) in Formula (52) and Formula(53).

Assume that precoding is performed on the symbol (set) (sp1(i) andsp2(i)) belonging to the fourth carrier group_2 in FIG. 56, using thematrix U42 as the precoding matrix Fp(i) in Formula (52) and Formula(53).

Assume that precoding is performed on the symbol (set) (sp1(i) andsp2(i)) belonging to the fifth carrier group_2 in FIG. 56, using thematrix U52 as the precoding matrix Fp(i) in Formula (52) and Formula(53).

As a first example, there is a method in which “U12≠U22, and U12≠U32,and U12≠U42, and U12≠U52, and U22≠U32, and U22≠U42, and U22≠U52, andU32≠U42, and U32≠U52, and U42≠U52” holds. When generalized, the methodis one in which “x is an integer equal to 1 or greater, y is an integerequal to 1 or greater, x≠y holds, and for all x and y satisfying theseconditions, Ux2≠Uy2 holds”.

As a second example, there is a method in which “U12≠U22, or U12≠U32, orU12≠U42, or U12≠U52, or U22≠U32, or U22≠U42, or U22≠U52, or U32≠U42, orU32≠U52, or U42≠U52” holds. When generalized, the method is one in which“there exists a set of x, y such that x is an integer equal to 1 orgreater, y is an integer equal to 1 or greater, x≠y holds, and Ux2≠Uy2holds”.

Additionally, the matrices U12, U22, U32, U42, and U52 are conceivablyexpressed by the matrix on the left side of Formula (5), the matrix onthe left side of Formula (6), the matrix on the left side of Formula(7), the matrix on the left side of Formula (8), the matrix on the leftside of Formula (9), the matrix on the left side of Formula (10), thematrix on the left side of Formula (11), the matrix on the left side ofFormula (12), the matrix on the left side of Formula (13), the matrix onthe left side of Formula (14), the matrix on the left side of Formula(15), the matrix on the left side of Formula (16), the matrix on theleft side of Formula (17), the matrix on the left side of Formula (18),the matrix on the left side of Formula (19), the matrix on the left sideof Formula (20), the matrix on the left side of Formula (21), the matrixon the left side of Formula (22), the matrix on the left side of Formula(23), the matrix on the left side of Formula (24), the matrix on theleft side of Formula (25), the matrix on the left side of Formula (26),the matrix on the left side of Formula (27), the matrix on the left sideof Formula (28), the matrix on the left side of Formula (29), the matrixon the left side of Formula (30), the matrix on the left side of Formula(31), the matrix on the left side of Formula (32), the matrix on theleft side of Formula (33), the matrix on the left side of Formula (34),the matrix on the left side of Formula (35), the matrix on the left sideof Formula (36), and the like, for example, but the matrices are notlimited thereto.

In other words, the precoding matrix Fp(i) may be any kind of matrixsuch as the matrix on the left side of Formula (5), the matrix on theleft side of Formula (6), the matrix on the left side of Formula (7),the matrix on the left side of Formula (8), the matrix on the left sideof Formula (9), the matrix on the left side of Formula (10), the matrixon the left side of Formula (11), the matrix on the left side of Formula(12), the matrix on the left side of Formula (13), the matrix on theleft side of Formula (14), the matrix on the left side of Formula (15),the matrix on the left side of Formula (16), the matrix on the left sideof Formula (17), the matrix on the left side of Formula (18), the matrixon the left side of Formula (19), the matrix on the left side of Formula(20), the matrix on the left side of Formula (21), the matrix on theleft side of Formula (22), the matrix on the left side of Formula (23),the matrix on the left side of Formula (24), the matrix on the left sideof Formula (25), the matrix on the left side of Formula (26), the matrixon the left side of Formula (27), the matrix on the left side of Formula(28), the matrix on the left side of Formula (29), the matrix on theleft side of Formula (30), the matrix on the left side of Formula (31),the matrix on the left side of Formula (32), the matrix on the left sideof Formula (33), the matrix on the left side of Formula (34), the matrixon the left side of Formula (35), and the matrix on the left side ofFormula (36).

Assume that precoding is performed on the symbol (set) (sp1(i) andsp2(i)) belonging to the first carrier group_3 in FIG. 56, using thematrix U13 as the precoding matrix Fp(i) in Formula (52) and Formula(53).

Assume that precoding is performed on the symbol (set) (sp1(i) andsp2(i)) belonging to the first carrier group_4 in FIG. 56, using thematrix U14 as the precoding matrix Fp(i) in Formula (52) and Formula(53).

Additionally, assume that precoding is performed on the symbol (set)(sp1(i) and sp2(i)) belonging to the second carrier group_4 in FIG. 56,using the matrix U24 as the precoding matrix Fp(i) in Formula (52) andFormula (53).

Assume that precoding is performed on the symbol (set) (sp1(i) andsp2(i)) belonging to the third carrier group_4 in FIG. 56, using thematrix U34 as the precoding matrix Fp(i) in Formula (52) and Formula(53).

As a first example, there is a method in which “U14≠U24, and U14≠U34,and U24≠U34” holds. When generalized, the method is one in which “x isan integer equal to 1 or greater, y is an integer equal to 1 or greater,x≠y holds, and for all x and y satisfying these conditions, Ux4≠Uy4holds”.

As a second example, there is a method in which “U14≠U24, or U14≠U34, orU24≠U34” holds. When generalized, the method is one in which “thereexists a set of x, y such that x is an integer equal to 1 or greater, yis an integer equal to 1 or greater, x≠y holds, and Ux4≠Uy4 holds”.

Additionally, the matrices U14, U24, and U34 are conceivably expressedby the matrix on the left side of Formula (5), the matrix on the leftside of Formula (6), the matrix on the left side of Formula (7), thematrix on the left side of Formula (8), the matrix on the left side ofFormula (9), the matrix on the left side of Formula (10), the matrix onthe left side of Formula (11), the matrix on the left side of Formula(12), the matrix on the left side of Formula (13), the matrix on theleft side of Formula (14), the matrix on the left side of Formula (15),the matrix on the left side of Formula (16), the matrix on the left sideof Formula (17), the matrix on the left side of Formula (18), the matrixon the left side of Formula (19), the matrix on the left side of Formula(20), the matrix on the left side of Formula (21), the matrix on theleft side of Formula (22), the matrix on the left side of Formula (23),the matrix on the left side of Formula (24), the matrix on the left sideof Formula (25), the matrix on the left side of Formula (26), the matrixon the left side of Formula (27), the matrix on the left side of Formula(28), the matrix on the left side of Formula (29), the matrix on theleft side of Formula (30), the matrix on the left side of Formula (31),the matrix on the left side of Formula (32), the matrix on the left sideof Formula (33), the matrix on the left side of Formula (34), the matrixon the left side of Formula (35), the matrix on the left side of Formula(36), and the like, for example, but the matrices are not limitedthereto.

In other words, the precoding matrix Fp(i) may be any kind of matrixsuch as the matrix on the left side of Formula (5), the matrix on theleft side of Formula (6), the matrix on the left side of Formula (7),the matrix on the left side of Formula (8), the matrix on the left sideof Formula (9), the matrix on the left side of Formula (10), the matrixon the left side of Formula (11), the matrix on the left side of Formula(12), the matrix on the left side of Formula (13), the matrix on theleft side of Formula (14), the matrix on the left side of Formula (15),the matrix on the left side of Formula (16), the matrix on the left sideof Formula (17), the matrix on the left side of Formula (18), the matrixon the left side of Formula (19), the matrix on the left side of Formula(20), the matrix on the left side of Formula (21), the matrix on theleft side of Formula (22), the matrix on the left side of Formula (23),the matrix on the left side of Formula (24), the matrix on the left sideof Formula (25), the matrix on the left side of Formula (26), the matrixon the left side of Formula (27), the matrix on the left side of Formula(28), the matrix on the left side of Formula (29), the matrix on theleft side of Formula (30), the matrix on the left side of Formula (31),the matrix on the left side of Formula (32), the matrix on the left sideof Formula (33), the matrix on the left side of Formula (34), the matrixon the left side of Formula (35), and the matrix on the left side ofFormula (36).

At this time, characteristics like the following may be included.

-   -   Like the “segment from time $1 to time $3” and “from time $4 to        time $9”, when the method of dividing frequencies is the same        (the frequency used by the first carrier group_1 and the        frequency used by the first carrier group_2 are the same, and        the frequency used by the second carrier group_1 and the        frequency used by the second carrier group_2 are the same, and        the frequency used by the third carrier group_1 and the        frequency used by the third carrier group_2 are the same, and        the frequency used by the fourth carrier group_1 and the        frequency used by the fourth carrier group_2 are the same, and        the frequency used by the fifth carrier group_1 and the        frequency used by the fifth carrier group_2 are the same), the        precoding matrix used by the Xth carrier group_1 (where X is 1,        2, 3, 4, 5) in the “segment from time $1 to time $3” and the        precoding matrix used by the Xth carrier group_2 in the “segment        from time $4 to time $9” may be the same or different.

For example, U11=U12 may hold, or U11≠U12 may hold. U21=U22 may hold, orU21≠U22 may hold. U31=U32 may hold, or U31≠U32 may hold. U41=U42 mayhold, or U41≠U42 may hold. U51=U52 may hold, or U51≠U52 may hold.

-   -   The method of dividing frequency may also be changed together        with time. For example, “from time $1 to time $3” in FIG. 56,        the frequency is divided into 5 from carrier #1 to carrier #25,        and five carrier groups are generated. Subsequently, “from time        $10 to time $11”, a single carrier group containing carrier #1        to carrier #25 is generated. Also, “from time $12 to time $14”,        the frequency is divided into 3 from carrier #1 to carrier #25,        and three carrier groups are generated.

Note that the method of dividing frequency is not limited to the methodin FIG. 56. The frequencies allocated to a certain user may be treatedas one carrier group, or two or more carrier groups may be generated.Also, it is sufficient for the number of carriers included in a carriergroup to be 1 or more.

The description described above using FIG. 56 states that “to transmitdata to a certain terminal (certain user) (terminal #p), the basestation or AP uses from carrier #1 to carrier #25, from time $1 to time$14”, but the base station or AP may also allocate from carrier #1 tocarrier #25, from time $1 to time $14 to transmit data to multipleterminals (multiple users). Hereinafter, this point will be described.Note that since the settings with respect to each carrier group of theprecoding matrix Fp(i) have been described earlier, a description isomitted here.

For example, as a first example, in FIG. 56, terminal allocation (userallocation) may be executed using time division.

For example, assume that the base station or AP uses “from time $1 totime $3” to transmit data to the terminal (user) p1 (that is, p=p1).Additionally, assume that the base station or AP uses “from time $4 totime $9” to transmit data to the terminal (user) p2 (that is, p=p2).Assume that the base station or AP uses “from time $10 to time $11” totransmit data to the terminal (user) p3 (that is, p=p3). Assume that thebase station or AP uses “from time $12 to time $14” to transmit data tothe terminal (user) p4 (that is, p=p4).

As a second example, in FIG. 56, terminal allocation (user allocation)may be executed using frequency division.

For example, assume that the base station or AP uses the first carriergroup_1 and the second carrier group_1 to transmit data to the terminal(user) p1 (that is, p=p1). Additionally, assume that the base station orAP uses the third carrier group_1, the fourth carrier group_1, and thefifth carrier group_1 to transmit data to the terminal (user) p2 (thatis, p=p2).

As a third example, in FIG. 56, terminal allocation (user allocation)may be executed using combined time and frequency division.

For example, assume that the base station or AP uses the first carriergroup_1, the first carrier group_2, the second carrier group_1, and thesecond carrier group_2 to transmit data to the terminal (user) p1 (thatis, p=p1). Additionally, assume that the base station or AP uses thethird carrier group_1, the fourth carrier group_1, and the fifth carriergroup_1 to transmit data to the terminal (user) p2 (that is, p=p2).Assume that the base station or AP uses the third carrier group_2 andthe fourth carrier group_2 to transmit data to the terminal (user) p3(that is, p=p3). Assume that the base station or AP uses the fifthcarrier group_2 to transmit data to the terminal (user) p4 (that is,p=p4). Assume that the base station or AP uses the first carrier group_3to transmit data to the terminal (user) p5 (that is, p=p5). Assume thatthe base station or AP uses the first carrier group_4 to transmit datato the terminal (user) p6 (that is, p=p6). Assume that the base stationor AP uses the second carrier group_4 and the third carrier group_4 totransmit data to the terminal (user) p7 (that is, p=p7).

Note that in the description described above, the method of configuringthe carrier groups is not limited to FIG. 56. For example, as long asthere are one or more carriers included in a carrier group, the carriergroups may be configured in any way. Also, the intervals of timeincluded in a carrier group are not limited to the configuration in FIG.56. Also, the frequency division method, the time division method, andthe combined time and frequency division method for user allocation isnot limited to the examples described above, and it is possible to carryout an embodiment by executing any kind of division.

In accordance with examples like the above, by “changing the precodingmatrix periodically or regularly” in a process similar to “changing thephase periodically or regularly” described in Embodiment 1 to Embodiment11, Supplement 1 to Supplement 4, and the like, the advantageous effectsdescribed in Embodiment 1 to Embodiment 11, Supplement 1 to Supplement4, and the like may be obtained.

Embodiment 14

Embodiment 1, Embodiment 3, and the like describe switching betweenperforming phase change and not performing phase change for the phasechange before precoding (weight combining) and/or the phase change afterprecoding (weight combining), or in other words, in the phase changer305B, the phase changer 305A, the phase changer 3801B, and the phasechanger 3801A in FIGS. 3, 4, 26, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47,48, 49, and the like.

Embodiment 1, Supplement 2, and the like describe switching betweenperforming phase change and not performing phase change (switchingbetween performing a CDD (CSD) process and not performing a CDD (CSD)process) in the phase changer 309B of FIGS. 3, 4, 26, 38, 39, and thelike. Obviously, the switching between performing phase change and notperforming phase change (switching between performing a CDD (CSD)process and not performing a CDD (CSD) process) may also be executed inthe phase changer 309A in FIGS. 57 and 59.

In the present embodiment, a supplementary explanation of this pointwill be given.

Embodiment 1, Embodiment 3, and the like describe switching betweenperforming phase change and not performing phase change for the phasechange before precoding (weight combining) and/or the phase change afterprecoding (weight combining), or in other words, in the phase changer305B, the phase changer 305A, the phase changer 3801B, and the phasechanger 3801A in FIGS. 3, 4, 26, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47,48, 49, and the like, but this phase change is described as an operationof the user #p signal processor 102_p in FIGS. 1 and 52.

Consequently, in the signal processor for each user, a “selectionbetween performing phase change and not performing phase change in thephase changer 305B, the phase changer 305A, the phase changer 3801B, andthe phase changer 3801A in FIGS. 3, 4, 26, 38, 39, 40, 41, 42, 43, 44,45, 46, 47, 48, 49, and the like” is executed. In other words, in theuser #p signal processor 102_p in FIGS. 1 and 52, for p from 1 to M, a“selection between performing phase change and not performing phasechange in the phase changer 305B, the phase changer 305A, the phasechanger 3801B, and the phase changer 3801A in FIGS. 3, 4, 26, 38, 39,40, 41, 42, 43, 44, 45, 46, 47, 48, 49, and the like” is executedindividually.

Embodiment 1, Supplement 2, and the like describe switching betweenperforming phase change and not performing phase change (switchingbetween performing a CDD (CSD) process and not performing a CDD (CSD)process) in the phase changer 309B of FIGS. 3, 4, 26, 38, 39, and thelike. Obviously, the switching between performing phase change and notperforming phase change (switching between performing a CDD (CSD)process and not performing a CDD (CSD) process) in the phase changer309A in FIGS. 57 and 59 is described. This process is described as anoperation of the user #p signal processor 102_p in FIGS. 1 and 52.

Consequently, in the signal processor for each user, a “selectionbetween performing phase change and not performing phase change (aselection between performing a CDD (CSD) process and not performing aCDD (CSD) process) in the phase changer 309B in FIGS. 3, 4, 26, 38, 39,and the like”, and/or a “selection between performing phase change andnot performing phase change (a selection between performing a CDD (CSD)process and not performing a CDD (CSD) process) in the phase changer309A in FIGS. 57 and 59” is executed. In other words, in the user #psignal processor 102_p in FIGS. 1 and 52, for p from 1 to M, a“selection between performing phase change and not performing phasechange (a selection between performing a CDD (CSD) process and notperforming a CDD (CSD) process) in the phase changer 309B in FIGS. 3, 4,26, 38, 39, and the like”, and/or a “selection between performing phasechange and not performing phase change (a selection between performing aCDD (CSD) process and not performing a CDD (CSD) process) in the phasechanger 309A in FIGS. 57 and 59” is executed individually.

Also, Embodiment 1 and Embodiment 3 describe a base station or AP usingcontrol information symbols included in the other symbols 603 or 703 ofFIGS. 8 and 9, for example, to transmit “information related toperforming phase change or not performing phase change in the phasechanger 305B, the phase changer 305A, the phase changer 3801B, and thephase changer 3801A in FIGS. 3, 4, 26, 38, 39, 40, 41, 42, 43, 44, 45,46, 47, 48, 49, and the like”, and also describe a base station or APusing the preamble 1001, 1101 and the control information symbols 1002,1102 of FIGS. 10 and 11, for example, to transmit “information relatedto performing phase change or not performing phase change in the phasechanger 305B, the phase changer 305A, the phase changer 3801B, and thephase changer 3801A in FIGS. 3, 4, 26, 38, 39, 40, 41, 42, 43, 44, 45,46, 47, 48, 49, and the like”.

In the present embodiment, a supplementary explanation of this pointwill be given.

For example, assume that the base station or AP transmits a modulatedsignal addressed to the user #p with the frame configuration of FIGS. 8and 9. As an example, assume that the modulated signals of multiplestreams are transmitted.

At this time, assume that the control information symbols included inthe other symbols 603 and 703 of FIGS. 8 and 9 include the “informationabout performing phase change or not performing phase change” A601and/or the “information about performing phase change or not performingphase change (information about performing a CDD (CSD) process or notperforming a CDD (CSD) process)” A602 illustrated in FIG. 60.

The “information about performing phase change or not performing phasechange” A601 is information indicating whether the base station or AP“has performed phase change or has not performed phase change in thephase changer 305B, the phase changer 305A, the phase changer 3801B, andthe phase changer 3801A in FIGS. 3, 4, 26, 38, 39, 40, 41, 42, 43, 44,45, 46, 47, 48, 49, and the like”. The user #p terminal, by obtainingthe “information about performing phase change or not performing phasechange” A601, performs demodulation/decoding of the data symbols of theuser #p modulated signals transmitted by the base station or AP.

The “information about performing phase change or not performing phasechange (information about performing a CDD (CSD) process or notperforming a CDD (CSD) process)” A602 is information indicating whetherthe base station or AP “has performed phase change or has not performedphase change (has or has not performed the CDD (CSD) process) in thephase changer 309A and the phase changer 309B in FIGS. 3, 4, 26, 38, 39,57, 59, and the like”. The user #p terminal, by obtaining the“information about performing phase change or not performing phasechange (information about performing a CDD (CSD) process or notperforming a CDD (CSD) process)” A602, performs demodulation/decoding ofthe data symbols of the user #p modulated signals transmitted by thebase station or AP.

Note that the “information about performing phase change or notperforming phase change” A601 may be generated individually for eachuser. In other words, for example, “information about performing phasechange or not performing phase change” A601 addressed to user #1,“information about performing phase change or not performing phasechange” A601 addressed to user #2, “information about performing phasechange or not performing phase change” A601 addressed to user #3, and soon may exist. Note that the information does not have to be generatedfor each user.

Similarly, the “information about performing phase change or notperforming phase change (information about performing a CDD (CSD)process or not performing a CDD (CSD) process)” A602 may also begenerated individually for each user. In other words, for example,“information about performing phase change or not performing phasechange (information about performing a CDD (CSD) process or notperforming a CDD (CSD) process)” A602 addressed to user #1, “informationabout performing phase change or not performing phase change(information about performing a CDD (CSD) process or not performing aCDD (CSD) process)” A602 addressed to user #2, “information aboutperforming phase change or not performing phase change (informationabout performing a CDD (CSD) process or not performing a CDD (CSD)process)” A602 addressed to user #3, and so on may exist. Note that theinformation does not have to be generated for each user.

Note that in FIG. 60, an example is described in which both the“information about performing phase change or not performing phasechange” A601 and the “information about performing phase change or notperforming phase change (information about performing a CDD (CSD)process or not performing a CDD (CSD) process)” A602 exist in thecontrol information symbols, but a configuration in which only oneexists is also acceptable.

For example, assume that the base station or AP transmits a modulatedsignal addressed to the user #p with the frame configuration of FIGS. 10and 11. As an example, the case of transmitting the modulated signals ofmultiple streams will be described.

At this time, assume that the control information symbols 1002 and 1102included in the preamble 1001 and 1101 of FIGS. 10 and 11 include the“information about performing phase change or not performing phasechange” A601 and/or the “information about performing phase change ornot performing phase change (information about performing a CDD (CSD)process or not performing a CDD (CSD) process)” A602 illustrated in FIG.60.

The “information about performing phase change or not performing phasechange” A601 is information indicating whether the base station or AP“has performed phase change or has not performed phase change in thephase changer 305B, the phase changer 305A, the phase changer 3801B, andthe phase changer 3801A in FIGS. 3, 4, 26, 38, 39, 40, 41, 42, 43, 44,45, 46, 47, 48, 49, and the like”. The user #p terminal, by obtainingthe “information about performing phase change or not performing phasechange” A601, performs demodulation/decoding of the data symbols of theuser #p modulated signals transmitted by the base station or AP.

The “information about performing phase change or not performing phasechange (information about performing a CDD (CSD) process or notperforming a CDD (CSD) process)” A602 is information indicating whetherthe base station or AP “has performed phase change or has not performedphase change (has or has not performed the CDD (CSD) process) in thephase changer 309A and the phase changer 309B in FIGS. 3, 4, 26, 38, 39,57, 59, and the like”. The user #p terminal, by obtaining the“information about performing phase change or not performing phasechange (information about performing a CDD (CSD) process or notperforming a CDD (CSD) process)” A602, performs demodulation/decoding ofthe data symbols of the user #p modulated signals transmitted by thebase station or AP.

Note that the “information about performing phase change or notperforming phase change” A601 may be generated individually for eachuser. In other words, for example, “information about performing phasechange or not performing phase change” A601 addressed to user #1,“information about performing phase change or not performing phasechange” A601 addressed to user #2, “information about performing phasechange or not performing phase change” A601 addressed to user #3, and soon may exist. Note that the information does not have to be generatedfor each user.

Similarly, the “information about performing phase change or notperforming phase change (information about performing a CDD (CSD)process or not performing a CDD (CSD) process)” A602 may also begenerated individually for each user. In other words, for example,“information about performing phase change or not performing phasechange (information about performing a CDD (CSD) process or notperforming a CDD (CSD) process)” A602 addressed to user #1, “informationabout performing phase change or not performing phase change(information about performing a CDD (CSD) process or not performing aCDD (CSD) process)” A602 addressed to user #2, “information aboutperforming phase change or not performing phase change (informationabout performing a CDD (CSD) process or not performing a CDD (CSD)process)” A602 addressed to user #3, and so on may exist. Note that theinformation does not have to be generated for each user.

Note that in FIG. 60, an example is described in which both the“information about performing phase change or not performing phasechange” A601 and the “information about performing phase change or notperforming phase change (information about performing a CDD (CSD)process or not performing a CDD (CSD) process)” A602 exist in thecontrol information symbols, but a configuration in which only oneexists is also acceptable.

Next, operation of the reception apparatus will be described.

Since the configuration and operation of the reception apparatus hasbeen described using FIG. 19 in Embodiment 1, a description will beomitted for the content that has been described in Embodiment 1.

The control information decoder 1909 of FIG. 19 acquires the informationof FIG. 60 included in the input signal, and outputs a controlinformation signal 1901 including the information.

The signal processor 1911 executes demodulation/decoding of the datasymbols on the basis of the information of FIG. 60 included in thecontrol information signal 1901, and acquires and outputs received data1912.

By performing as above, the advantageous effects described in thisspecification may be obtained.

Embodiment 15

In Embodiment 1 to Embodiment 11, Supplement 1 to Supplement 4, and thelike, if both “the phase changer 305B, the phase changer 305A, the phasechanger 3801B, and the phase changer 3801A in FIGS. 3, 4, 26, 38, 39,40, 41, 42, 43, 44, 45, 46, 47, 48, 49, and the like” and thecomputations in the weight combiner 303 are considered as a whole, suchas by referencing Formula (37), Formula (42), Formula (43), Formula(45), Formula (47), and Formula (48), for example, the precoding matrixcorresponds to switching according to i.

Also, in the weight combiner 303, in the case of using Formula (21),Formula (22), Formula (23), Formula (24), Formula (25), Formula (26),Formula (27), and Formula (28), for example, the precoding matrixcorresponds to switching according to i.

This point has been described in Embodiment 13, and FIGS. 58 and 59illustrate the configuration of the user #p signal processor 102_p ofFIGS. 1 and 52.

In the present embodiment, an operation similar to Embodiment 13, namelyswitching between performing a precoding matrix change and notperforming a precoding matrix change in the weight combiner A401 inFIGS. 58 and 59, will be described.

FIGS. 58 and 59 described in Embodiment 13 correspond to the user #psignal processor 102_p of FIGS. 1 and 52. Consequently, in the signalprocessor for each user, a selection of whether to perform a precodingmatrix change or not to perform a precoding matrix change is executed bythe weight combiner A401. In other words, in the user #p signalprocessor 102_p of FIGS. 1 and 52, for p from 1 to M, a selection ofwhether to perform a precoding matrix change or not to perform aprecoding matrix change is executed individually by the weight combinerA401.

For example, assume that the base station or AP transmits a modulatedsignal addressed to the user #p with the frame configuration of FIGS. 8and 9. As an example, assume that the modulated signals of multiplestreams are transmitted.

At this time, assume that the control information symbols included inthe other symbols 603 and 703 of FIGS. 8 and 9 include the “informationabout performing a precoding matrix change or not performing a precodingmatrix change” A701 and/or the “information about performing phasechange or not performing phase change (information about performing aCDD (CSD) process or not performing a CDD (CSD) process)” A602illustrated in FIG. 61.

The “information about performing a precoding matrix change or notperforming a precoding matrix change” A701 is information indicatingwhether the base station or AP “will perform a precoding matrix changeor not perform a precoding matrix change in the weight combiner A401 inFIGS. 58 and 59”. The user #p terminal, by obtaining the “informationabout performing a precoding matrix change or not performing a precodingmatrix change” A701, performs demodulation/decoding of the data symbolsof the user #p modulated signals transmitted by the base station or AP.

The “information about performing phase change or not performing phasechange (information about performing a CDD (CSD) process or notperforming a CDD (CSD) process)” A602 is information indicating whetherthe base station or AP “has performed phase change or has not performedphase change (has or has not performed the CDD (CSD) process) in thephase changer 309A and the phase changer 309B in FIGS. 58, 59, and thelike”. The user #p terminal, by obtaining the “information aboutperforming phase change or not performing phase change (informationabout performing a CDD (CSD) process or not performing a CDD (CSD)process)” A602, performs demodulation/decoding of the data symbols ofthe user #p modulated signals transmitted by the base station or AP.

Note that the “information about performing a precoding matrix change ornot performing a precoding matrix change” A701 may be generatedindividually for each user. In other words, for example, “informationabout performing a precoding matrix change or not performing a precodingmatrix change” A701 addressed to user #1, “information about performinga precoding matrix change or not performing a precoding matrix change”A701 addressed to user #2, “information about performing a precodingmatrix change or not performing a precoding matrix change” A701addressed to user #3, and so on may exist. Note that the informationdoes not have to be generated for each user.

Similarly, the “information about performing phase change or notperforming phase change (information about performing a CDD (CSD)process or not performing a CDD (CSD) process)” A602 may also begenerated individually for each user. In other words, for example,“information about performing phase change or not performing phasechange (information about performing a CDD (CSD) process or notperforming a CDD (CSD) process)” A602 addressed to user #1, “informationabout performing phase change or not performing phase change(information about performing a CDD (CSD) process or not performing aCDD (CSD) process)” A602 addressed to user #2, “information aboutperforming phase change or not performing phase change (informationabout performing a CDD (CSD) process or not performing a CDD (CSD)process)” A602 addressed to user #3, and so on may exist. Note that theinformation does not have to be generated for each user.

Note that in FIG. 61, an example is described in which both the“information about performing a precoding matrix change or notperforming a precoding matrix change” A701 and the “information aboutperforming phase change or not performing phase change (informationabout performing a CDD (CSD) process or not performing a CDD (CSD)process)” A602 exist in the control information symbols, but aconfiguration in which only one exists is also acceptable.

For example, assume that the base station or AP transmits a modulatedsignal addressed to the user #p with the frame configuration of FIGS. 10and 11. As an example, the case of transmitting the modulated signals ofmultiple streams will be described.

At this time, assume that the control information symbols 1002 and 1102included in the preamble 1001 and 1101 of FIGS. 10 and 11 include the“information about performing a precoding matrix change or notperforming a precoding matrix change” A701 and/or the “information aboutperforming phase change or not performing phase change (informationabout performing a CDD (CSD) process or not performing a CDD (CSD)process)” A602 illustrated in FIG. 61.

The “information about performing a precoding matrix change or notperforming a precoding matrix change” A701 is information indicatingwhether the base station or AP “will perform a precoding matrix changeor not perform a precoding matrix change in the weight combiner A401 inFIGS. 58 and 59”. The user #p terminal, by obtaining the “informationabout performing a precoding matrix change or not performing a precodingmatrix change” A701, performs demodulation/decoding of the data symbolsof the user #p modulated signals transmitted by the base station or AP.

The “information about performing phase change or not performing phasechange (information about performing a CDD (CSD) process or notperforming a CDD (CSD) process)” A602 is information indicating whetherthe base station or AP “has performed phase change or has not performedphase change (has or has not performed the CDD (CSD) process) in thephase changer 309A and the phase changer 309B in FIGS. 58, 59, and thelike”. The user #p terminal, by obtaining the “information aboutperforming phase change or not performing phase change (informationabout performing a CDD (CSD) process or not performing a CDD (CSD)process)” A602, performs demodulation/decoding of the data symbols ofthe user #p modulated signals transmitted by the base station or AP.

Note that the “information about performing a precoding matrix change ornot performing a precoding matrix change” A701 may be generatedindividually for each user. In other words, for example, “informationabout performing a precoding matrix change or not performing a precodingmatrix change” A701 addressed to user #1, “information about performinga precoding matrix change or not performing a precoding matrix change”A701 addressed to user #2, “information about performing a precodingmatrix change or not performing a precoding matrix change” A701addressed to user #3, and so on may exist. Note that the informationdoes not have to be generated for each user.

Similarly, the “information about performing phase change or notperforming phase change (information about performing a CDD (CSD)process or not performing a CDD (CSD) process)” A602 may also begenerated individually for each user. In other words, for example,“information about performing phase change or not performing phasechange (information about performing a CDD (CSD) process or notperforming a CDD (CSD) process)” A602 addressed to user #1, “informationabout performing phase change or not performing phase change(information about performing a CDD (CSD) process or not performing aCDD (CSD) process)” A602 addressed to user #2, “information aboutperforming phase change or not performing phase change (informationabout performing a CDD (CSD) process or not performing a CDD (CSD)process)” A602 addressed to user #3, and so on may exist. Note that theinformation does not have to be generated for each user.

Note that in FIG. 61, an example is described in which both the“information about performing a precoding matrix change or notperforming a precoding matrix change” A701 and the “information aboutperforming phase change or not performing phase change (informationabout performing a CDD (CSD) process or not performing a CDD (CSD)process)” A602 exist in the control information symbols, but aconfiguration in which only one exists is also acceptable.

Next, operation of the reception apparatus will be described.

Since the configuration and operation of the reception apparatus hasbeen described using FIG. 19 in Embodiment 1, a description will beomitted for the content that has been described in Embodiment 1.

The control information decoder 1909 of FIG. 19 acquires the informationof FIG. 61 included in the input signal, and outputs a controlinformation signal 1901 including the information.

The signal processor 1911 executes demodulation/decoding of the datasymbols on the basis of the information of FIG. 61 included in thecontrol information signal 1901, and acquires and outputs received data1912.

By performing as above, the advantageous effects described in thisspecification may be obtained.

(Supplement 5)

Although not illustrated in FIGS. 3, 4, 26, 38, 39, 57, 58, and thelike, each of the pilot symbol signal (pa(t)) (351A), the pilot symbolsignal (pb(t)) (351B), the preamble signal 352, and the controlinformation symbol signal 353 may also be a signal subjected toprocessing such as phase change.

Embodiment 16

Embodiments such as Embodiment 1, Embodiment 2, and Embodiment 3describe a configuration in which the weight combiner 303, the phasechanger 305A, and/or the phase changer 305B exist in FIGS. 3, 4, 26, 40,41, 42, 43, 44, 45, 46, 47, and 48, for example. The following describesa configuration method for obtaining favorable reception quality in anenvironment in which direct waves are dominant or an environment inwhich multipath or the like exists.

First, a method of phase change when the weight combiner 303 and thephase changer 305B exist, like in FIGS. 3, 4, 41, 45, 47, and the like,will be described.

For example, as described in the embodiments described thus far, assumethat the phase change value in the phase changer 305B is given as yp(i).Note that i is taken to be the symbol number. For example, i is aninteger equal to 0 or greater.

For example, the phase change value yp(i) assumes N periods, andprepares N values as phase change values. Note that N is taken to be aninteger equal to 2 or greater. Additionally, for example, Phase[0],Phase[1], Phase[2], Phase[3], . . . , Phase[N−2], Phase[N−1] areprepared as the N values. In other words, the result is Phase[k], wherek is taken to be an integer from 0 to N−1. Additionally, Phase[k] istaken to be a real number from 0 radians to 2π radians. Also, u is takento be an integer from 0 to N−1, v is taken to be an integer from 0 toN−1, and assume that u≠v. Additionally, assume that Phase[u]≠Phase[v]holds for all u, v satisfying these conditions. Note that the method ofsetting the phase change value yp(i) when assuming the period N has beendescribed in other embodiments of this specification. Additionally, Mvalues are extracted from Phase[0], Phase[1], Phase[2], Phase[3], . . ., Phase[N−2], Phase[N−1], and these M values are expressed asPhase_1[0], Phase_1[1], Phase_1[2], . . . , Phase_1[M−2], Phase_1[M−1].In other words, the result is Phase_1[k], where k is taken to be aninteger from 0 to M−1. Note that M is taken to be an integer less than Nand equal to 2 or greater.

At this time, assume that the phase change value yp(i) takes any valueamong Phase_1[0], Phase_1[1], Phase_1[2], . . . , Phase_1[M−2],Phase_1[M−1]. Additionally, assume that each of Phase_1[0], Phase_1[1],Phase_1[2], . . . , Phase_1[M−2], Phase_1[M−1] is used at least once asthe phase change value yp(i).

For example, one example is a method in which the period of the phasechange value yp(i) is M. In this case, the following formula holds.yp(i=u+v×M)=Phase_1[u]  (54)Note that u is an integer from 0 to M−1. Also, v is taken to be aninteger equal to 0 or greater.

Also, the weight combining process and the phase change process may beexecuted individually in the weight combiner 303 and the phase changer305B as in FIG. 3 and the like, or the process in the weight combiner303 and the process in the phase changer 305B may be performed by afirst signal processor 6200 as in FIG. 62. Note that in FIG. 62, partswhich operate similarly to FIG. 3 are denoted with the same numbers.

For example, in Formula (3), provided that Fp is the matrix for weightcombining, and Pp is a matrix related to phase change, a matrixWp(=Pp×Fp) is prepared in advance. Additionally, the first signalprocessor 6200 in FIG. 62 may use the matrix Wp, a signal 301A (sp1(t)),and a signal 301B (sp2(t)) to generate signals 304A and 306B.

Additionally, the phase changers 309A, 309B, 3801A, and 3801B in FIGS.3, 4, 41, 45, and 47 may or may not execute signal processing for phasechange.

As above, by setting the phase change value yp(i), by the spatialdiversity effect, an advantageous effect may be obtained whereby thereception apparatus has a higher probability of being able to obtainfavorable reception quality in an environment in which direct waves aredominant or an environment in which multipath or the like exists.Furthermore, by reducing the number of values that the phase changevalue yp(i) may take as described above, there is a higher probabilityof being able to reduce the circuit scale of the transmission apparatusand the reception apparatus while also reducing the impact on the datareception quality.

Next, a method of phase change when the weight combiner 303, the phasechanger 305A, and the phase changer 305B exist, like in FIGS. 26, 40,43, 44, and the like, will be described.

As described in the other embodiments, assume that the phase changevalue in the phase changer 305B is given as yp(i). Note that i is takento be the symbol number. For example, i is an integer equal to 0 orgreater.

For example, the phase change value yp(i) assumes Nb periods, andprepares Nb values as phase change values. Note that Nb is taken to bean integer equal to 2 or greater. Additionally, for example, Phase_b[0],Phase_b[1], Phase_b[2], Phase_b[3], . . . , Phase_b[Nb−2], Phase_b[Nb−1]are prepared as the Nb values. In other words, the result is Phase_b[k],where k is taken to be an integer from 0 to Nb−1. Additionally,Phase_b[k] is taken to be a real number from 0 radians to 2π radians.Also, u is taken to be an integer from 0 to Nb−1, v is taken to be aninteger from 0 to Nb−1, and assume that u≠v. Additionally, assume thatPhase_b[u]≠Phase_b[v] holds for all u, v satisfying these conditions.Note that the method of setting the phase change value yp(i) whenassuming the period Nb has been described in other embodiments of thisspecification. Additionally, Mb values are extracted from Phase_b[0],Phase_b[1], Phase_b[2], Phase_b[3], . . . , Phase_b[Nb−2],Phase_b[Nb−1], and these Mb values are expressed as Phase_1[0],Phase_1[1], Phase_1[2], . . . , Phase_1[Mb−2], Phase_1[Mb−1]. In otherwords, the result is Phase_1[k], where k is taken to be an integer from0 to Mb−1. Note that Mb is taken to be an integer less than Nb and equalto 2 or greater.

At this time, assume that the phase change value yp(i) takes any valueamong Phase_1[0], Phase_1[1], Phase_1[2], . . . , Phase_1[Mb−2],Phase_1[Mb−1]. Additionally, assume that each of Phase_1[0], Phase_1[1],Phase_1[2], . . . , Phase_1[Mb−2], Phase_1[Mb−1] is used at least onceas the phase change value yp(i).

For example, one example is a method in which the period of the phasechange value yp(i) is Mb. In this case, the following holds.yp(i=u+v×Mb)=Phase_1[u]  (55)Note that u is an integer from 0 to Mb−1. Also, v is taken to be aninteger equal to 0 or greater.

As described in the other embodiments, assume that the phase changevalue in the phase changer 305A is given as Yp(i). Note that i is takento be the symbol number. For example, i is an integer equal to 0 orgreater. For example, the phase change value Yp(i) assumes Na periods,and prepares Na values as phase change values. Note that Na is taken tobe an integer equal to 2 or greater. Additionally, for example,Phase_a[0], Phase_a[1], Phase_a[2], Phase_a[3], . . . , Phase_a[Na−2],Phase_a[Na−1] are prepared as the Na values. In other words, the resultis Phase_a[k], where k is taken to be an integer from 0 to Na−1.Additionally, Phase_a[k] is taken to be a real number from 0 radians to2π radians. Also, u is taken to be an integer from 0 to Na−1, v is takento be an integer from 0 to Na−1, and assume that u≠v. Additionally,assume that Phase_a[u]≠Phase_a[v] holds for all u, v satisfying theseconditions. Note that the method of setting the phase change value Yp(i)when assuming the period Na has been described in other embodiments ofthis specification. Additionally, Ma values are extracted fromPhase_a[0], Phase_a[1], Phase_a[2], Phase_a[3], . . . , Phase_a[Na−2],Phase_a[Na−1], and these Ma values are expressed as Phase_2[0],Phase_2[1], Phase_2[2], . . . , Phase_2[Ma−2], Phase_2[Ma−1]. In otherwords, the result is Phase_2[k], where k is taken to be an integer from0 to Ma−1. Note that Ma is taken to be an integer less than Na and equalto 2 or greater.

At this time, assume that the phase change value Yp(i) takes any valueamong Phase_2[0], Phase_2[1], Phase_2[2], . . . , Phase_2[Ma−2],Phase_2[Ma−1]. Additionally, assume that each of Phase_2[0], Phase_2[1],Phase_2[2], . . . , Phase_2[Ma−2], Phase_2[Ma−1] is used at least onceas the phase change value Yp(i).

For example, one example is a method in which the period of the phasechange value Yp(i) is Ma. In this case, the following holds.Yp(i=u+v×Ma)=Phase_2[u]  (56)Note that u is an integer from 0 to Ma−1. Also, v is taken to be aninteger equal to 0 or greater.

Also, the weight combining process and the phase change process may beexecuted individually in the weight combiner 303 and the phase changers305A, 305B as in FIGS. 26, 40, 43, 44, and the like, or the process inthe weight combiner 303 and the process in the phase changers 305A, 305Bmay be performed by a second signal processor 6300 as in FIG. 63. Notethat in FIG. 63, parts which operate similarly to FIGS. 26, 40, 43, and44 are denoted with the same numbers.

For example, in Formula (42), provided that Fp is the matrix for weightcombining, and Pp is the matrix related to phase change, the matrixWp(=Pp×Fp) is prepared in advance. Additionally, the second signalprocessor 6300 in FIG. 63 may use the matrix Wp, the signal 301A(sp1(t)), and the signal 301B (sp2(t)) to generate signals 306A and306B.

Additionally, the phase changers 309A, 309B, 3801A, and 3801B in FIGS.26, 40, 43, and 44 may or may not execute signal processing for phasechange.

Also, Na and Nb may have the same value or different values.Additionally, Ma and Mb may have the same value or different values.

As above, by setting the phase change value yp(i) and the phase changevalue Yp(i), by the spatial diversity effect, an advantageous effect maybe obtained whereby the reception apparatus has a higher probability ofbeing able to obtain favorable reception quality in an environment inwhich direct waves are dominant or an environment in which multipath orthe like exists. Furthermore, by reducing the number of values that thephase change value yp(i) may take or reducing the number of values thatthe phase change value Yp(i) may take as described above, there is ahigher probability of being able to reduce the circuit scale of thetransmission apparatus and the reception apparatus while also reducingthe impact on the data reception quality.

Note that the present embodiment is highly likely to be effective whenapplied to the methods of phase change described in the otherembodiments of this specification. However, it is also possible to carryout an embodiment similarly by applying the present embodiment to othermethods of phase change.

Embodiment 17

In the present embodiment, a method of phase change when the weightcombiner 303 and the phase changer 305B exist, like in FIGS. 3, 4, 41,45, 47, and the like, will be described.

For example, as described in the other embodiments, assume that thephase change value in the phase changer 305B is given as yp(i). Notethat i is taken to be the symbol number. For example, i is an integerequal to 0 or greater.

For example, assume that the phase change value yp(i) has N periods.Note that N is taken to be an integer equal to 2 or greater.Additionally, Phase[0], Phase[1], Phase[2], Phase[3], . . . ,Phase[N−2], Phase[N−1] are prepared as the N values. In other words, theresult is Phase[k], where k is taken to be an integer from 0 to N−1.Additionally, Phase[k] is taken to be a real number from 0 radians to 2πradians. Also, u is taken to be an integer from 0 to N−1, v is taken tobe an integer from 0 to N−1, and assume that u≠v. Additionally, assumethat Phase[u]≠Phase[v] holds for all u, v satisfying these conditions.In this case, assume that Phase[k] is expressed by the followingformula. Note that k is taken to be an integer from 0 to N−1.

$\begin{matrix}{{Phase}\mspace{14mu}{\lbrack k\rbrack = \frac{k\;\pi}{N}}} & (57)\end{matrix}$

However, assume that the units of Formula (57) are radians.Additionally, Phase[0], Phase[1], Phase[2], Phase[3], . . . ,Phase[N−2], and Phase[N−1] are used such that the period of the phasechange value yp(i) becomes N. To achieve the period N, the values may bearranged as Phase[0], Phase[1], Phase[2], Phase[3], . . . , Phase[N−2],Phase[N−1] or the like. Note that to achieve the period N, for example,assume that the following holds.yp(i=u+v×N)=yp(i=u+(v+1)×N)  (58)Note that u is an integer from 0 to N−1, and v is an integer equal to 0or greater. Additionally, Formula (58) holds for all u, v satisfyingthese conditions.

Note that the weight combining process and the phase change process maybe executed individually in the weight combiner 303 and the phasechanger 305B as in FIG. 3 and the like, or the process in the weightcombiner 303 and the process in the phase changer 305B may be performedby a first signal processor 6200 as in FIG. 62. Note that in FIG. 62,parts which operate similarly to FIG. 3 are denoted with the samenumbers.

For example, in Formula (3), provided that Fp is the matrix for weightcombining, and Pp is a matrix related to phase change, a matrixWp(=Pp×Fp) is prepared in advance. Additionally, the first signalprocessor 6200 in FIG. 62 may use the matrix Wp, a signal 301A (sp1(t)),and a signal 301B (sp2(t)) to generate signals 304A and 306B.

Additionally, the phase changers 309A, 309B, 3801A, and 3801B in FIGS.3, 4, 41, 45, and 47 may or may not execute signal processing for phasechange.

As above, by setting the phase change value yp(i), by the spatialdiversity effect, an advantageous effect may be obtained whereby thereception apparatus has a higher probability of being able to obtainfavorable reception quality in an environment in which direct waves aredominant or an environment in which multipath or the like exists.Furthermore, by limiting the number of values that the phase changevalue yp(i) may take as described above, there is a higher probabilityof being able to reduce the circuit scale of the transmission apparatusand the reception apparatus while also reducing the impact on the datareception quality.

Next, a method of phase change when the weight combiner 303, the phasechanger 305A, and the phase changer 305B exist, like in FIGS. 26, 40,43, 44, and the like, will be described.

As described in the other embodiments, assume that the phase changevalue in the phase changer 305B is given as yp(i). Note that i is takento be the symbol number. For example, i is an integer equal to 0 orgreater.

For example, assume that the phase change value yp(i) has Nb periods.Note that Nb is taken to be an integer equal to 2 or greater.Additionally, Phase_b[0], Phase_b[1], Phase_b[2], Phase_b[3], . . . ,Phase_b[Nb−2], Phase_b[Nb−1] are prepared as the Nb values. In otherwords, the result is Phase_b[k], where k is taken to be an integer from0 to Nb−1. Additionally, Phase_b[k] is taken to be a real number from 0radians to 2π radians. Also, u is taken to be an integer from 0 to Nb−1,v is taken to be an integer from 0 to Nb−1, and assume that u≠v.Additionally, assume that Phase_b[u]≠Phase_b[v] holds for all u, vsatisfying these conditions. In this case, assume that Phase_b[k] isexpressed by the following formula. Note that k is taken to be aninteger from 0 to Nb−1.

$\begin{matrix}{{Phase}\mspace{14mu}{\_ b}{\lbrack k\rbrack = \frac{k\;\pi}{Nb}}} & (59)\end{matrix}$

However, assume that the units of Formula (59) are radians.Additionally, Phase_b[0], Phase_b[1], Phase_b[2], Phase_b[3], . . . ,Phase_b[Nb−2], and Phase_b[Nb−1] are used such that the period of thephase change value yp(i) becomes Nb. To achieve the period Nb, thevalues may be arranged as Phase_b[0], Phase_b[1], Phase_b[2],Phase_b[3], . . . , Phase_b[Nb−2], Phase_b[Nb−1] or the like. Note thatto achieve the period Nb, for example, assume that the following holds.yp(i=u+v×Nb)=yp(i=u+(v+1)×Nb)  (60)Note that u is an integer from 0 to Nb−1, and v is an integer equal to 0or greater. Additionally, Formula (60) holds for all u, v satisfyingthese conditions.

As described in the other embodiments, assume that the phase changevalue in the phase changer 305A is given as Yp(i). Note that i is takento be the symbol number. For example, i is an integer equal to 0 orgreater. For example, assume that the phase change value Yp(i) has Naperiods. Note that Na is taken to be an integer equal to 2 or greater.Additionally, Phase_a[0], Phase_a[1], Phase_a[2], Phase_a[3], . . . ,Phase_a[Na−2], Phase_a[Na−1] are prepared as the Na values. In otherwords, the result is Phase_a[k], where k is taken to be an integer from0 to Na−1. Additionally, Phase_a[k] is taken to be a real number from 0radians to 2π radians. Also, u is taken to be an integer from 0 to Na−1,v is taken to be an integer from 0 to Na−1, and assume that u≠v.Additionally, assume that Phase_a[u]≠Phase_a[v] holds for all u, vsatisfying these conditions. In this case, assume that Phase_a[k] isexpressed by the following formula. Note that k is taken to be aninteger from 0 to Na−1.

$\begin{matrix}{{Phase}\mspace{14mu}{\_ a}{\lbrack k\rbrack = \frac{k\;\pi}{Na}}} & (61)\end{matrix}$

However, assume that the units of Formula (61) are radians.Additionally, Phase_a[0], Phase_a[1], Phase_a[2], Phase_a[3], . . . ,Phase_a[Na−2], and Phase_a[Na−1] are used such that the period of thephase change value Yp(i) becomes Na. To achieve the period Na, thevalues may be arranged as Phase_a[0], Phase_a[1], Phase_a[2],Phase_a[3], . . . , Phase_a[Na−2], Phase_a[Na−1] or the like. Note thatto achieve the period Na, for example, assume that the following holds.Yp(i=u+v×Na)=Yp(i=u+(v+1)×Na)  (62)Note that u is an integer from 0 to Na−1, and v is an integer equal to 0or greater. Additionally, Formula (62) holds for all u, v satisfyingthese conditions.

Note that the weight combining process and the phase change process maybe executed individually in the weight combiner 303 and the phasechangers 305A, 305B as in FIGS. 26, 40, 43, 44, and the like, or theprocess in the weight combiner 303 and the process in the phase changers305A, 305B may be performed by a second signal processor 6300 as in FIG.63. Note that in FIG. 63, parts which operate similarly to FIGS. 26, 40,43, and 44 are denoted with the same numbers.

For example, in Formula (42), provided that Fp is the matrix for weightcombining, and Pp is the matrix related to phase change, the matrixWp(=Pp×Fp) is prepared in advance. Additionally, the second signalprocessor 6300 in FIG. 63 may use the matrix Wp, the signal 301A(sp1(t)), and the signal 301B (sp2(t)) to generate signals 306A and306B.

Additionally, the phase changers 309A, 309B, 3801A, and 3801B in FIGS.26, 40, 43, and 44 may or may not execute signal processing for phasechange.

Also, Na and Nb may have the same value or different values.

As above, by setting the phase change value yp(i) and the phase changevalue Yp(i), by the spatial diversity effect, an advantageous effect maybe obtained whereby the reception apparatus has a higher probability ofbeing able to obtain favorable reception quality in an environment inwhich direct waves are dominant or an environment in which multipath orthe like exists. Furthermore, by limiting the number of values that thephase change value yp(i) and the phase change value Yp(i) may take asdescribed above, there is a higher probability of being able to reducethe circuit scale of the transmission apparatus and the receptionapparatus while also reducing the impact on the data reception quality.

Note that the present embodiment is highly likely to be effective whenapplied to the methods of phase change described in the otherembodiments of this specification. However, it is also possible to carryout an embodiment similarly by applying the present embodiment to othermethods of phase change.

Obviously, the present embodiment and Embodiment 16 may also be combinedand carried out. In other words, M phase change values may be extractedfrom Formula (57). Also, Mb phase change values may be extracted fromFormula (59), and Ma phase change values may be extracted from Formula(61).

Embodiment 18

In the present embodiment, a method of phase change when the weightcombiner 303 and the phase changer 305B exist, like in FIGS. 3, 4, 41,45, 47, and the like, will be described.

For example, as described in the other embodiments, assume that thephase change value in the phase changer 305B is given as yp(i). Notethat i is taken to be the symbol number. For example, i is an integerequal to 0 or greater.

For example, assume that the phase change value yp(i) has N periods.Note that N is taken to be an integer equal to 2 or greater.Additionally, Phase[0], Phase[1], Phase[2], Phase[3], . . . ,Phase[N−2], Phase[N−1] are prepared as the N values. In other words, theresult is Phase[k], where k is taken to be an integer from 0 to N−1.Additionally, Phase[k] is taken to be a real number from 0 radians to 2πradians. Also, u is taken to be an integer from 0 to N−1, v is taken tobe an integer from 0 to N−1, and assume that u≠v. Additionally, assumethat Phase[u]≠Phase[v] holds for all u, v satisfying these conditions.In this case, assume that Phase[k] is expressed by the followingformula. Note that k is taken to be an integer from 0 to N−1.

$\begin{matrix}{{Phase}\mspace{14mu}{\lbrack k\rbrack = \frac{k \times 2 \times \pi}{N}}} & (63)\end{matrix}$

However, assume that the units of Formula (63) are radians.Additionally, Phase [0], Phase[1], Phase[2], Phase[3], . . . ,Phase[N−2], and Phase[N−1] are used such that the period of the phasechange value yp(i) becomes N. To achieve the period N, the values may bearranged as Phase[0], Phase[1], Phase[2], Phase[3], . . . , Phase[N−2],Phase[N−1] or the like. Note that to achieve the period N, for example,assume that the following holds.yp(i=u+v×N)=yp(i=u+(v+1)×N)  (64)Note that u is an integer from 0 to N−1, and v is an integer equal to 0or greater. Additionally, Formula (64) holds for all u, v satisfyingthese conditions.

Note that the weight combining process and the phase change process maybe executed individually in the weight combiner 303 and the phasechanger 305B as in FIG. 3 and the like, or the process in the weightcombiner 303 and the process in the phase changer 305B may be performedby a first signal processor 6200 as in FIG. 62. Note that in FIG. 62,parts which operate similarly to FIG. 3 are denoted with the samenumbers.

For example, in Formula (3), provided that Fp is the matrix for weightcombining, and Pp is a matrix related to phase change, a matrixWp(=Pp×Fp) is prepared in advance. Additionally, the first signalprocessor 6200 in FIG. 62 may use the matrix Wp, a signal 301A (sp1(t)),and a signal 301B (sp2(t)) to generate signals 304A and 306B.

Additionally, the phase changers 309A, 309B, 3801A, and 3801B in FIGS.3, 4, 41, 45, and 47 may or may not execute signal processing for phasechange.

As above, by setting the phase change value yp(i), in the complex plane,values that the phase change value yp(i) may take are made to existuniformly from the perspective of phase, and a spatial diversity effectis obtained. With this arrangement, an advantageous effect may beobtained whereby the reception apparatus has a higher probability ofbeing able to obtain favorable reception quality in an environment inwhich direct waves are dominant or an environment in which multipath orthe like exists.

Next, a method of phase change when the weight combiner 303, the phasechanger 305A, and the phase changer 305B exist, like in FIGS. 26, 40,43, 44, and the like, will be described.

As described in the other embodiments, assume that the phase changevalue in the phase changer 305B is given as yp(i). Note that i is takento be the symbol number. For example, i is an integer equal to 0 orgreater.

For example, assume that the phase change value yp(i) has Nb periods.Note that Nb is taken to be an integer equal to 2 or greater.Additionally, Phase_b[0], Phase_b[1], Phase_b[2], Phase_b[3], . . . ,Phase_b[Nb−2], Phase_b[Nb−1] are prepared as the Nb values. In otherwords, the result is Phase_b[k], where k is taken to be an integer from0 to Nb−1. Additionally, Phase_b[k] is taken to be a real number from 0radians to 2π radians. Also, u is taken to be an integer from 0 to Nb−1,v is taken to be an integer from 0 to Nb−1, and assume that u≠v.Additionally, assume that Phase_b[u]≠Phase_b[v] holds for all u, vsatisfying these conditions. In this case, assume that Phase_b[k] isexpressed by the following formula. Note that k is taken to be aninteger from 0 to Nb−1.

$\begin{matrix}{{Phase}\mspace{14mu}{\_ b}{\lbrack k\rbrack = \frac{k \times 2 \times \;\pi}{Nb}}} & (65)\end{matrix}$

However, assume that the units of Formula (65) are radians.Additionally, Phase_b[0], Phase_b[1], Phase_b[2], Phase_b[3], . . . ,Phase_b[Nb−2], and Phase_b[Nb−1] are used such that the period of thephase change value yp(i) becomes Nb. To achieve the period Nb, thevalues may be arranged as Phase_b[0], Phase_b[1], Phase_b[2],Phase_b[3], . . . , Phase_b[Nb−2], Phase_b[Nb−1] or the like. Note thatto achieve the period Nb, for example, assume that the following holds.yp(i=u+v×Nb)=yp(i=u+(v+1)×Nb)  (66)Note that u is an integer from 0 to Nb−1, and v is an integer equal to 0or greater. Additionally, Formula (66) holds for all u, v satisfyingthese conditions.

As described in the other embodiments, assume that the phase changevalue in the phase changer 305A is given as Yp(i). Note that i is takento be the symbol number. For example, i is an integer equal to 0 orgreater. For example, assume that the phase change value Yp(i) has Naperiods. Note that Na is taken to be an integer equal to 2 or greater.Additionally, Phase_a[0], Phase_a[1], Phase_a[2], Phase_a[3], . . . ,Phase_a[Na−2], Phase_a[Na−1] are prepared as the Na values. In otherwords, the result is Phase_a[k], where k is taken to be an integer from0 to Na−1. Additionally, Phase_a[k] is taken to be a real number from 0radians to 2π radians. Also, u is taken to be an integer from 0 to Na−1,v is taken to be an integer from 0 to Na−1, and assume that u≠v.Additionally, assume that Phase_a[u]≠Phase_a[v] holds for all u, vsatisfying these conditions. In this case, assume that Phase_a[k] isexpressed by the following formula. Note that k is taken to be aninteger from 0 to Na−1.

$\begin{matrix}{{Phase}\mspace{14mu}{\_ a}{\lbrack k\rbrack = \frac{k \times 2 \times \;\pi}{Na}}} & (67)\end{matrix}$

However, assume that the units of Formula (67) are radians.Additionally, Phase_a[0], Phase_a[1], Phase_a[2], Phase_a[3], . . . ,Phase_a[Na−2], and Phase_a[Na−1] are used such that the period of thephase change value w(i) becomes Na. To achieve the period Na, the valuesmay be arranged as Phase_a[0], Phase_a[1], Phase_a[2], Phase_a[3], . . ., Phase_a[Na−2], Phase_a[Na−1] or the like. Note that to achieve theperiod Na, for example, assume that the following holds.Yp(i=u+v×Na)=Yp(i=u+(v+1)×Na)  (68)Note that u is an integer from 0 to Na−1, and v is an integer equal to 0or greater. Additionally, Formula (68) holds for all u, v satisfyingthese conditions.

Note that the weight combining process and the phase change process maybe executed individually in the weight combiner 303 and the phasechangers 305A, 305B as in FIGS. 26, 40, 43, 44, and the like, or theprocess in the weight combiner 303 and the process in the phase changers305A, 305B may be performed by a second signal processor 6300 as in FIG.63. Note that in FIG. 63, parts which operate similarly to FIGS. 26, 40,43, and 44 are denoted with the same numbers.

For example, in Formula (42), provided that Fp is the matrix for weightcombining, and Pp is the matrix related to phase change, the matrixWp(=Pp×Fp) is prepared in advance. Additionally, the second signalprocessor 6300 in FIG. 63 may use the matrix Wp, the signal 301A(sp1(t)), and the signal 301B (sp2(t)) to generate signals 306A and306B.

Additionally, the phase changers 309A, 309B, 3801A, and 3801B in FIGS.26, 40, 43, and 44 may or may not execute signal processing for phasechange.

Also, Na and Nb may have the same value or different values.

As above, by setting the phase change value yp(i) and the phase changevalue Yp(i), in the complex plane, values that the phase change valueyp(i) and the phase change value Yp(i) may take are made to existuniformly from the perspective of phase, and a spatial diversity effectis obtained. With this arrangement, an advantageous effect may beobtained whereby the reception apparatus has a higher probability ofbeing able to obtain favorable reception quality in an environment inwhich direct waves are dominant or an environment in which multipath orthe like exists.

Note that the present embodiment is highly likely to be effective whenapplied to the methods of phase change described in the otherembodiments of this specification. However, it is also possible to carryout an embodiment similarly by applying the present embodiment to othermethods of phase change.

Obviously, the present embodiment and Embodiment 16 may also be combinedand carried out. In other words, M phase change values may be extractedfrom Formula (63). Also, Mb phase change values may be extracted fromFormula (65), and Ma phase change values may be extracted from Formula(67).

(Supplement 6)

Regarding the modulation scheme, even if a modulation scheme other thanthe modulation schemes described in this specification is used, it ispossible to carry out the embodiments and other content described inthis specification. For example, non-uniform (NU)-QAM, π/2 shift BPSK,π/4 shift QPSK, a PSK scheme shifted by a phase of certain value, andthe like may also be used.

Additionally, the phase changers 309A and 309B may also be cyclic delaydiversity (CDD) or cyclic shift diversity (CSD).

In this specification, for example, in FIGS. 3, 4, 26, 33, 38, 39, 40,41, 42, 43, 44, 45, 46, 47, 48, 58, 59, and the like, the mapped signalsp1(t) and the mapped signal sp2(t) are described as transmittingmutually different data, but are not limited thereto. In other words,the mapped signal sp1(t) and the mapped signal sp2(t) may also transmitidentical data. For example, when the symbol number i=a (where a is aninteger equal to 0 or greater, for example), the mapped signal sp1(i=a)and the mapped signal sp2(i=a) may transmit identical data.

Note that the method by which the mapped signal sp1(i=a) and the mappedsignal sp2(i=a) transmit identical data is not limited to the abovetechnique. For example, the mapped signal sp1(i=a) and the mapped signalsp2(i=b) may also transmit identical data (where b is an integer equalto 0 or greater, and a≠b). Furthermore, multiple symbols of sp1(i) maybe used to transmit a first data sequence, while multiple symbols ofsp2(i) may be used to transmit a second data sequence.

Embodiment 19

In this specification, in the “user #p signal processor” 102_p providedin the base station of FIG. 1, FIG. 52, or the like, multiple precodingmatrices switchable by a weight combiner (for example, 303) in FIGS. 3,4, 26, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 58, 59, and the likeare provided, or in other words, multiple codebooks are provided. Thebase station may be configured to select, on the basis of feedbackinformation transmitted by the user #p, that is, the terminal #p, aprecoding matrix for generating modulated signal to transmit to the user#p from among the switchable precoding matrices, or in other words, fromamong the switchable codebooks, and the “user #p signal processor” 102_pmay be configured to execute the computational operations of theprecoding matrix. Note that the selection of the precoding matrix, thatis, the codebook in the base station may be decided by the base station.Hereinafter, this point will be described.

FIG. 64 illustrates the relationship between the base station and theuser #p, that is, the terminal #p. A base station 6400 transmits amodulated signal (namely, 6410_p), and the terminal #p 6401_p receivesthe modulated signal transmitted by the base station.

For example, assume that the modulated signal transmitted by the basestation 6400 includes reference symbols, a reference signal, a preamble,or the like for estimating the channel state, such as the receptionelectric field strength.

The terminal #p 6401_p estimates the channel state from the referencesymbols, reference signal, preamble, or the like transmitted by the basestation. Subsequently, the terminal #p 6401_p transmits a modulatedsignal including information about the channel state to the base station(6411_p). Also, from the channel state, the terminal #p 6401_p maytransmit an indicator of a precoding matrix for generating a modulatedsignal that the base station transmits to the terminal #p.

On the basis of this feedback information obtained from the terminal,the base station 6400 selects a precoding matrix, that is, a codebook,to use for generating a modulated signal to transmit to the terminal #p.A specific example of operation is described below.

Assume that the weight combiner of the base station is capable of thecomputations of “matrix A, matrix B, matrix C, matrix D” as precodingmatrices, that is, codebooks, which may be used to generate a modulatedsignal to transmit to the user #p, that is, the terminal #p.Additionally, in order to generate a modulated signal for transmittingto the user #p, that is, the terminal #p, as the weight combining, inthe case of deciding to use “matrix A”, the base station executes weightcombining, that is, precoding, using “matrix A” in the weight combiner(for example, 303) in FIGS. 3, 4, 26, 38, 39, 40, 41, 42, 43, 44, 45,46, 47, 48, 58, 59, or the like provided in the base station, and thebase station generates a modulated signal for the user #p, that is, theterminal #p. Subsequently, the base station transmits the generatedmodulated signal.

Similarly, in order to generate a modulated signal for transmitting tothe user #p, that is, the terminal #p, as the weight combining, in thecase of deciding to use “matrix B”, the base station executes weightcombining, that is, precoding, using “matrix B” in the weight combiner(for example, 303) in FIGS. 3, 4, 26, 38, 39, 40, 41, 42, 43, 44, 45,46, 47, 48, 58, 59, or the like provided in the base station, and thebase station generates a modulated signal for the user #p, that is, theterminal #p. Subsequently, the base station transmits the generatedmodulated signal.

In order to generate a modulated signal for transmitting to the user #p,that is, the terminal #p, as the weight combining, in the case ofdeciding to use “matrix C”, the base station executes weight combining,that is, precoding, using “matrix C” in the weight combiner (forexample, 303) in FIGS. 3, 4, 26, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47,48, 58, 59, or the like provided in the base station, and the basestation generates a modulated signal for the user #p, that is, theterminal #p. Subsequently, the base station transmits the generatedmodulated signal.

In order to generate a modulated signal for transmitting to the user #p,that is, the terminal #p, as the weight combining, in the case ofdeciding to use “matrix D”, the base station executes weight combining,that is, precoding, using “matrix D” in the weight combiner (forexample, 303) in FIGS. 3, 4, 26, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47,48, 58, 59, or the like provided in the base station, and the basestation generates a modulated signal for the user #p, that is, theterminal #p. Subsequently, the base station transmits the generatedmodulated signal.

Note that in the example described above, an example in which four typesof precoding matrices, that is, codebooks, which may be used by the basestation to generate a modulated signal are provided is described, butthe number of provided matrices is not limited to 4, and it is possibleto carry out the embodiment similarly insofar as multiple matrices areprovided. Also, the phase change described in this specification may ormay not be performed after the weight combining. At this time, whetherto perform or not perform phase change may be switched according to acontrol signal or the like.

Similarly, even in the multiplexing signal processor 104 of FIG. 1,multiple matrices (which may also be called codebooks) for generating anoutput signal (modulated signal) may be prepared, and on the basis offeedback information from the terminal, the base station may select amatrix to use in the multiplexing signal processor 104 of FIG. 1, anduse the selected matrix to generate an output signal. Note that theselection of the matrix to use may be decided by the base station.Hereinafter, this point will be described. Note that since the exchangebetween the base station and the terminal has been described above usingFIG. 64, a description is omitted here.

Assume that the multiplexing signal processor 104 of the base station iscapable of the computations of “matrix α, matrix β, matrix γ, matrix δ”as precoding matrices, that is, codebooks, which may be used to generatea modulated signal to transmit to the terminal. Additionally, in thecase in which the base station decides to use “matrix α” as the processof the multiplexing signal processor, in the multiplexing signalprocessor in FIG. 1 or the like provided in the base station,multiplexing signal processing is performed using “matrix α”, amodulated signal is generated, and the base station transmits thegenerated modulated signal.

Similarly, in the case in which the base station decides to use “matrixβ” as the process of the multiplexing signal processor, in themultiplexing signal processor in FIG. 1 or the like provided in the basestation, multiplexing signal processing is performed using “matrix β”, amodulated signal is generated, and the base station transmits thegenerated modulated signal.

In the case in which the base station decides to use “matrix γ” as theprocess of the multiplexing signal processor, in the multiplexing signalprocessor in FIG. 1 or the like provided in the base station,multiplexing signal processing is performed using “matrix γ”, amodulated signal is generated, and the base station transmits thegenerated modulated signal.

In the case in which the base station decides to use “matrix δ” as theprocess of the multiplexing signal processor, in the multiplexing signalprocessor in FIG. 1 or the like provided in the base station,multiplexing signal processing is performed using “matrix δ”, amodulated signal is generated, and the base station transmits thegenerated modulated signal.

Note that in the example described above, an example in which four typesof matrices, that is, codebooks, which may be used by the base stationto generate a modulated signal are provided is described, but the numberof provided matrices is not limited to 4, and it is possible to carryout the embodiment similarly insofar as multiple matrices are provided.

Assume that the multiplexing signal processor 7000_p of FIG. 52 in thebase station is capable of the computations of “matrix P, matrix Q,matrix R, matrix S” as precoding matrices, that is, codebooks, which maybe used to generate a modulated signal to transmit to the user #p, thatis, the terminal #p. Note that p is taken to be an integer from 1 to M.Subsequently, in order to generate a modulation scheme for transmittingto the user #p, that is, the terminal #p, as the multiplexing signalprocessing, in the case of deciding to use “matrix P”, the base stationexecutes multiplexing signal processing using “matrix P” in themultiplexing signal processor 7000_p of FIG. 52 provided in the basestation, and the base station generates a modulated signal for the user#p, that is, the terminal #p. Subsequently, the base station transmitsthe generated modulated signal.

Similarly, in order to generate a modulation scheme for transmitting tothe user #p, that is, the terminal #p, as the multiplexing signalprocessing, in the case of deciding to use “matrix Q”, the base stationexecutes multiplexing signal processing using “matrix Q” in themultiplexing signal processor 7000_p of FIG. 52 provided in the basestation, and the base station generates a modulated signal for the user#p, that is, the terminal #p. Subsequently, the base station transmitsthe generated modulated signal.

In order to generate a modulation scheme for transmitting to the user#p, that is, the terminal #p, as the multiplexing signal processing, inthe case of deciding to use “matrix R”, the base station executesmultiplexing signal processing using “matrix R” in the multiplexingsignal processor 7000_p of FIG. 52 provided in the base station, and thebase station generates a modulated signal for the user #p, that is, theterminal #p. Subsequently, the base station transmits the generatedmodulated signal.

In order to generate a modulation scheme for transmitting to the user#p, that is, the terminal #p, as the multiplexing signal processing, inthe case of deciding to use “matrix S”, the base station executesmultiplexing signal processing using “matrix S” in the multiplexingsignal processor 7000_p of FIG. 52 provided in the base station, and thebase station generates a modulated signal for the user #p, that is, theterminal #p. Subsequently, the base station transmits the generatedmodulated signal.

Note that in the example described above, an example in which four typesof precoding matrices, that is, codebooks, which may be used by the basestation to generate a modulated signal are provided is described, butthe number of provided matrices is not limited to 4, and it is possibleto carry out the embodiment similarly insofar as multiple matrices areprovided.

As above, even if each section operates as described in the presentembodiment, the advantageous effects described in this specification maybe obtained similarly. Therefore, it is also possible to carry out thepresent embodiment in combination with the other embodiments describedin this specification, and the advantageous effects described in eachembodiment may be obtained similarly.

Embodiment 20

In the description from Embodiment 1 to Embodiment 19, the case of theconfiguration in FIG. 1, FIG. 52, and the like is described as theconfiguration of the base station or AP. In other words, the case inwhich the base station is capable of transmitting modulated signals tomultiple users, that is, multiple terminals, at the same time isdescribed. In the present embodiment, an example will be described for acase in which the configuration of the base station or AP is aconfiguration like that of FIG. 65.

FIG. 65 illustrates a configuration of the base station or AP in thepresent embodiment.

An error-correcting coder 6502 accepts data 6501 and a control signal6500 as input, and on the basis of information related toerror-correcting coding included in the control signal 6500, such asinformation about the error-correcting coding scheme and the code rate,for example, the error-correcting coder 6502 executes error-correctingcoding, and outputs error-correcting coded data 6503.

A mapper 6504 accepts the control signal 6500 and the error-correctingcoded data 6503 as input, and on the basis of information about themodulation scheme included in the control signal 6500, executes mappingto output a stream #1 baseband signal 6505_1 and a stream #2 basebandsignal 6505_2.

A signal processor 6506 accepts the control signal 6500, the stream #1baseband signal 6505_1, and the stream #2 baseband signal 6505_2 asinput, performs signal processing on the stream #1 baseband signal6505_1 and the stream #2 baseband signal 6505_2 on the basis ofinformation related to the transmission method included in the controlsignal 6500, and generates and outputs a first modulated signal 6506_Aand a second modulated signal 6506_B.

A radio section 6507_A accepts the first modulated signal 6506_A and thecontrol signal 6500 as input, performs processing such as frequencyconversion on the first modulated signal 6506_A, and outputs a firsttransmission signal 6508_A. The first transmission signal 6508_A isoutput from an antenna section #A 6509_A as a radio wave.

Similarly, a radio section 6507_B accepts the second modulated signal6506_B and the control signal 6500 as input, performs processing such asfrequency conversion on the second modulated signal 6506_B, and outputsa second transmission signal 6508_B. The second transmission signal6508_B is output from an antenna section #B 6509_B as a radio wave.

Note that the first transmission signal 6508_A and the secondtransmission signal 6508_B are signals with identical times andidentical frequencies (bands).

The signal processor 6506 in FIG. 65 is provided with the configurationof any of FIGS. 3, 4, 26, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48,58, and 59, for example. At this time, the signal corresponding to thesignal of 6505_1 in FIG. 65 becomes 301A, the signal corresponding tothe signal of 6505_2 becomes 301B, and the signal corresponding to thesignal of 6500 becomes 300. Additionally, in FIGS. 3, 4, 26, 38, 39, 40,41, 42, 43, 44, 45, 46, 47, 48, 58, and 59, dual output signals exist,and these dual output signals correspond to the signals 6506_A and6506_B in FIG. 65.

Note that the signal processor 6506 in FIG. 65 is provided with a singleconfiguration of any of FIGS. 3, 4, 26, 38, 39, 40, 41, 42, 43, 44, 45,46, 47, 48, 58, and 59, for example. In other words, the configurationmay be considered to be a transmission apparatus supporting single-usermultiple-input multiple-output (MIMO).

Consequently, in the case of carrying out each embodiment fromEmbodiment 1 to Embodiment 19, the base station transmits modulatedsignals to multiple terminals in a certain time band and a certainfrequency band, as illustrated in FIG. 24, but the base station providedwith the transmission apparatus of FIG. 65 transmits, in a certain timeband and a certain frequency band, modulated signals to a singleterminal. Consequently, in each embodiment from Embodiment 1 toEmbodiment 19, the base station provided with the transmission apparatusof FIG. 65 executes an exchange with terminal #p=1, and carries out eachembodiment from Embodiment 1 to Embodiment 19. Even with thisarrangement, each embodiment from Embodiment 1 to Embodiment 19 may becarried out, and the advantageous effects described in each embodimentmay be obtained similarly.

Note that the base station provided with the transmission apparatus ofFIG. 65 is capable of exchanging data with multiple terminals byutilizing time-division multiple access (TDMA), frequency-divisionmultiple access (FDMA), and/or code-division multiple access (CDMA).

Obviously, the embodiments described in this specification and othercontent may also be combined plurally.

Also, each embodiment is merely exemplary, and for example, even ifexamples of “modulation schemes, error-correcting coding schemes (suchas the error-correcting codes, code lengths, and code rates to use),control information, and the like” are given, it is still possible tocarry out a similar configuration even in the case of applying different“modulation schemes, error-correcting coding schemes (such as theerror-correcting codes, code lengths, and code rates to use), controlinformation, and the like”.

Regarding the modulation scheme, even if a modulation scheme other thanthe modulation schemes described in this specification is used, it ispossible to carry out the embodiments and other content described inthis specification. For example, amplitude phase-shift keying (APSK)(such as 16APSK, 64APSK, 128APSK, 256APSK, 1024APSK, and 4096APSK, forexample), pulse-amplitude modulation (PAM) (such as 4PAM, 8PAM, 16PAM,64PAM, 128PAM, 256PAM, 1024PAM, and 4096PAM, for example), phase-shiftkeying (such as BPSK, QPSK, 8PSK, 16PSK, 64PSK, 128PSK, 256PSK, 1024PSK,and 4096PSK, for example), quadrature amplitude modulation (QAM) (suchas 4QAM, 8QAM, 16QAM, 64QAM, 128QAM, 256QAM, 1024QAM, and 4096QAM, forexample), and the like may be applied, and in each modulation scheme,uniform mapping or non-uniform mapping may be used. Also, a method ofarranging 2, 4, 8, 16, 64, 128, 256, 1024 signal points or the like inthe I-Q plane (a modulation scheme having 2, 4, 8, 16, 64, 128, 256,1024 signal points or the like) is not limited to the signal pointarrangement methods of the modulation schemes illustrated in thisspecification.

In this specification, it is conceivable to provide the transmissionapparatus in communication/broadcasting equipment such as a broadcastingstation, a base station, an access point, a terminal, or a mobile phone,for example. Meanwhile, it is conceivable to provide the receptionapparatus in communication equipment such as a television, a radio, aterminal, a personal computer, a mobile phone, an access point, or abase station. It is also conceivable for the transmission apparatus andthe reception apparatus in the present disclosure to be a piece ofequipment including a communication function, in which the equipment isable to connect, over some kind of interface, to an apparatus forexecuting an application, such as a television, a radio, a personalcomputer, or a mobile phone. Also, in the present embodiment, symbolsother than data symbols, such as pilot symbols (a preamble, unique word,postamble, reference symbols, or the like), control information symbols,and the like, for example, may also be arranged in a frame in any way.Additionally, although designated as pilot symbols and controlinformation symbols herein, such symbols may be given any kind ofdesignation, as the function itself is what is important.

For example, in a transmitter/receiver, it is sufficient for the pilotsymbols to be known symbols modulated using PSK modulation (or symbolstransmitted by a transmitter that the receiver is able to know bysynchronizing with the transmitter). The receiver uses these symbols toexecute frequency synchronization, time synchronization, the estimation(for each modulated signal) of channel state information (CSI), signaldetection, and the like.

Also, the control information symbols are symbols for transmittinginformation that needs to be transmitted to the other party (such as themodulation scheme, error-correcting coding scheme, and the code rate ofthe error-correcting coding scheme used for communication, andhigher-layer settings information, for example) in order to achieve thecommunication of information other than data (of an application or thelike).

Note that the present disclosure is not limited to the embodiments, andthat various modifications are possible. For example, in eachembodiment, the case of carrying out the present disclosure as acommunication apparatus is described, but the configuration is notlimited thereto, and it is also possible to execute the communicationmethod as software.

Note that, for example, a program that executes the above communicationmethod may be stored in read-only memory (ROM) in advance, and theprogram may be run by a central processing unit (CPU).

In addition, a program that executes the above communication method maybe stored on a computer-readable storage medium, the program stored onthe storage medium may be loaded into the random access memory (RAM) ofa computer, and the computer may be made to operate by following theprogram.

Additionally, each component of each of the above embodiments typicallymay be realized an integrated circuit, that is, a large-scaleintegration (LSI) chip. These components may be realized individually asseparate chips, or alternatively, all or some of the configuration ofeach embodiment may be included on a single chip. Although LSI isdiscussed herein, the circuit integration methodology may also bereferred to as integrated circuit (IC), system LSI, super LSI, or ultraLSI, depending on the degree of integration. Furthermore, the circuitintegration methodology is not limited to LSI, and may be also berealized with special-purpose circuits or general-purpose processors. Afield-programmable gate array (FPGA) capable of being programmed afterLSI fabrication, or a reconfigurable processor whose internal LSIcircuit cell connections and settings may be reconfigured, may also beused. Furthermore, if circuit integration technology that may besubstituted for LSI appears as a result of progress in semiconductortechnology or another derived technology, obviously the new technologymay be used to integrate the function blocks. Biotechnology applicationsand the like are also a possibility.

In this specification, a variety of frame configurations are described.A modulated signal with a frame configuration described in thisspecification is assumed to be transmitted using a multi-carrier schemesuch as OFDM by, for example, a base station (AP) provided with thetransmission apparatus of FIG. 1. At this time, when a terminal (user)which is communicating with the base station (AP) transmits a modulatedsignal, the modulated signal transmitted by the terminal may beconsidered to be the application method referred to as thesingle-carrier scheme (the base station (AP), is able to transmit a datasymbol group to multiple terminals at the same time by using OFDM, whilein addition, the terminals become able to reduce power consumption byusing the single-carrier scheme).

Additionally, a time-division duplex (TDD) scheme whereby a terminaltransmits a modulated signal using a portion of the frequency band usedby the modulated signal transmitted by the base station (AP) may also beapplied.

The present disclosure is useful in a communication apparatus such as abase station.

The invention claimed is:
 1. A terminal apparatus comprising: atransmitter which, in operation, transmits capability informationindicative of capabilities of the terminal apparatus, the transmittedcapability information including at least one main capability field anda plurality of dependent capability fields, each of the plurality ofdependent capability fields being associated with one of the at leastone main capability field, wherein the at least one main capabilityfield includes a multi-stream capability field for indicating whethermulti-stream is supported or not, and the plurality of dependentcapability fields include a precoding field for indicating a precodingmethod that is supported by the terminal apparatus; a receiver which, inoperation, receives N multiplexed signal streams (N is an integer equalto 2 or greater) that are generated based on the multi-stream capabilityfield in the transmitted capability information by a base stationapparatus that receives the transmitted capability information; andsignal processing circuitry which, in operation, performs signalprocessing on the N multiplexed signal streams based on the at least onemain capability field and the plurality of dependent capability fieldsin the transmitted capability information, wherein the N multiplexedsignal streams are generated by the base station apparatus by generatinga transmission stream based on the at least one main capability fieldand the plurality of dependent capability fields in the transmittedcapability information and performing spatial multiplexing ontransmission streams.
 2. The terminal apparatus according to claim 1,wherein the at least one main capability field includes an OFDM(Orthogonal Frequency Division Multiplexing) capability field forindicating whether an OFDM scheme is supported or not; and when the OFDMcapability field indicates that the OFDM scheme is supported for theterminal apparatus, one or more OFDM symbols are generated by applyingOFDM processing on a symbol sequence.
 3. The terminal apparatusaccording to claim 1, wherein the plurality of dependent capabilityfields include a Phase Hopping capability field for indicating whetherPhase Hopping is supported or not; and when the Phase Hopping capabilityfield indicates that the Phase Hopping is supported for the terminalapparatus, the Phase Hopping is performed by the base station apparatusto generate the transmission stream.
 4. The terminal apparatus accordingto claim 1, wherein the plurality of dependent capability fields includea Modulation Coding Scheme (MCS) capability field for indicating MCSsupported by the terminal apparatus; and one or more transmissionstreams are generated by the base station apparatus by using the MCSindicated in the MCS capability field.
 5. The terminal apparatusaccording to claim 1, wherein when the multi-stream capability fieldindicates that the multi-stream is supported for the terminal apparatus,two or more transmission streams are generated by the base stationapparatus, and when the multi-stream capability field indicates that themulti-stream is not supported for the terminal apparatus, onetransmission stream is generated by the base station apparatus.
 6. Theterminal apparatus according to claim 1, wherein when the precodingfield indicates a specific precoding method, two transmission streamsare generated by the base station apparatus by using the indicatedprecoding method.
 7. A communication method for a terminal apparatus,the communication method comprising: transmitting capability informationindicative of capabilities of the terminal apparatus, the transmittedcapability information including at least one main capability field anda plurality of dependent capability fields, each of the plurality ofdependent capability fields being associated with one of the at leastone main capability field, wherein the at least one main capabilityfield includes a multi-stream capability field for indicating whethermulti-stream is supported or not, and the plurality of dependentcapability fields include a precoding field for indicating a precodingmethod that is supported by the terminal apparatus; receiving Nmultiplexed signal streams (N is an integer equal to 2 or greater) thatare generated based on the multi-stream capability field in thetransmitted capability information by a base station apparatus thatreceives the transmitted capability information; and performing signalprocessing on the N multiplexed signal streams based on the at least onemain capability field and the plurality of dependent capability fieldsin the transmitted capability information, wherein the N multiplexedsignal streams are generated by the base station apparatus by generatinga transmission stream based on the at least one main capability fieldand the plurality of dependent capability fields in the transmittedcapability information and performing spatial multiplexing ontransmission streams.
 8. The communication method according to claim 7,wherein the at least one main capability field includes an OFDM(Orthogonal Frequency Division Multiplexing) capability field forindicating whether an OFDM scheme is supported or not; and when the OFDMcapability field indicates that the OFDM scheme is supported for theterminal apparatus, one or more OFDM symbols are generated by applyingOFDM processing on a symbol sequence.
 9. The communication methodaccording to claim 7, wherein the plurality of dependent capabilityfields include a Phase Hopping capability field for indicating whetherPhase Hopping is supported or not; and when the Phase Hopping capabilityfield indicates that the Phase Hopping is supported for the terminalapparatus, the Phase Hopping is performed by the base station apparatusto generate the transmission stream.
 10. The communication methodaccording to claim 7, wherein the plurality of dependent capabilityfields include a Modulation Coding Scheme (MCS) capability field forindicating MCS supported by the terminal apparatus; and one or moretransmission streams are generated by the base station apparatus byusing the MCS indicated in the MCS capability field.
 11. Thecommunication method according to claim 7, wherein when the multi-streamcapability field indicates that the multi-stream is supported for theterminal apparatus, two or more transmission streams are generated bythe base station apparatus, and when the multi-stream capability fieldindicates that the multi-stream is not supported for the terminalapparatus, one transmission stream is generated by the base stationapparatus.
 12. The communication method according to claim 7, whereinwhen the precoding field indicates a specific precoding method, twotransmission streams are generated by the base station apparatus byusing the indicated precoding method.